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FILE NAME Cape Asbestos CAPE DATE 0000 DOC CAPE104 DOCUMENT DESCRIPTION Cape Document - Informational Publication on Amphibole Asbestos Legal - Tibbs Case Exhibit 2 Ferwcnaesigy: ELECTRONICALLY Asbestos History and Development stone which is combed and woven Asbestos has been known and used for its unique properties for many centuries Early Greek and Roman writings make many references to the material and mention specific sources including mines which at that time had already been worked out The essential characteristic of asbestos is that it will not burn but its name is a contradiction A Greek word it means inextinguishable or once burning cannot be quenched The paradox is perhaps explained by the use of asbestos in lamp wicks the most famous example being in the woven material used in the perpetual lamps of the Vestal Virgins Throughout industry however the fame of asbestos has been largely based on its incombustibility Plutarch who lived in the first century A.D. refers to rock yielding soft petrous filaments like yarn which are made into towels nets and women's head coverings which cannot be burned by fire but if any become soiled by use their owners throw them into a blazing fire and take them out bright and clean ELCTRONIALY The machine miniature stampers used by FILED Jacob Christian Schaffer - 1718- 1790 to 2023 produce Oct 10:18 AM - New asbestos discoveries RICHLAND Although some of the earlier accounts may have referred to the use of other varieties of asbestos it was clearly Chrysotile or White asbestos which figured largely in the early history But some time between 1803 1803 and 1806 a German geologist called Lichtenstein COM ON travelling near the village of Prieska in the Orange River Valley in South Africa came upon a mass of asbestos which was lavender blue in colour Apart from PLEAS its colour it had a different texture from Chrysotile and belonged to the Amphibole group of minerals It was named Crocidolite recorded and then forgotten - Almost ninety years were to pass before the material was mined commercially In the Middle Ages the Emperor Charlemagne is said to have impressed an enemy and prevented a war by exhibiting strange powers he threw his tablecloth into the fire and recovered it cleaned and unharmed Undoubtedly it was woven asbestos In 1250 the Venetian explorer Marco Polo records that he was shown unburnable cloth in Siberia and he learned of the existence of asbestos mines in the area References are also found in history to exploitation of other asbestos properties Archaeological finds dating back over 2,500 years show very early uses of fine asbestos fibre for reinforcing lightly fired pottery And a Greek doctor about 28 B.C. noted that if a tree is surrounded with linen made of asbestos the noise of the blows given by the axe will be deadened thereby and the tree may be cut down without making a noise Recognition even then of the acoustic insulation pro- perties of asbestos So through the centuries asbestos has been widely known and used But it remained an object more of curiosity and superstition than of practical value right up until 19th century 7 Long before this in 1847 immense deposits of Chry- 203CP41759 sotile asbestos had been discovered in Quebec by Sir William Logan the first Director of Geological Survey in Canada Once again it was a discovery too early for commercial exploitation Even as late as the 1870's asbestos was still a material for tricks and spectacles At that time asbestos was produced in Italy but its cost made any possible scale use uneconomic Mining of the rich Quebec deposits finally started at the beginning of the 1880's and since then there has been continual expansion Canada and Russia are today the largest producers of Chrysotile asbestos fibre Pee The Cape Asbestos Company Meanwhile the end of the 19th century saw development of that other major type of asbestos Amphibole Francis Oats a director of De Beers Consolidated Mines Ltd. the company controlling the diamond mines of South Africa formed in 1891 the Cape Mineral Syndicate to exploit Crocidolite which had recently been discovered in the Orange River Valley On December 28 1893 The Cape Asbestos Company Limited was incorporated in London its objective being to take over the Cape Mineral Syndicate's mining operations to manufacture in London and to acquire an Italian asbestos insulation factory as an outlet for Blue asbestos ELECTRONICAL Y The early days of the Cape Asbestos Company Limited were not rosy and for the years up to 1905 losses were reported far more often than profits During this period there was a year shutdown on mining because production far exceeded demand and Boer War which lasted from 1899 to 1902 led to yet another shutdown In the meantime the Italian factory carried on manufacture using white asbestos from other sources but fierce competition in white asbestos goods made profitable operation impossible Further setbacks followed some commercial some due to a severe three drought in South Africa that paralysed production and communications But the Company's confidence and persistence were rewarded By 1911. the directors were able to declare confidently that the value of the Company's land in South Africa was increasing and from then on profits were regularly being shown After the first world war fears were expressed that the Company's Blue asbestos mines might give out entirely in few years These fears have of course proved to be groundless but following investigations into alternative sources of supply the Company acquired in 1925 a number of mines in the Transvaal producing a coloured amphibole asbestos This had been discovered in 1907 at site called Amosa the initial letters of Asbestos Mines of South Africa The mineral became known as Amosite It had long stiff rigid fibres and whilst unsuitable for easy spinning proved itself ideal for the manufacture of insulating materials The world's supply of Amosite asbestos still comes largely from the South African mines of the Cape Group ELCTRONIAY Growth of asbestos cement industry Just before the turn of the century there took place one of the most significant events in asbestos history a FILED development that more than any other created a vast world market for the new raw material Ludwig - 2023 Hatschek the owner of a paper and board making plant at V^cklabrucknear Vienna began experimenting Oct with cement added to an asbestos millboard At about 80 cement and 20 fibre he discovered he had made 18 a new product 10:18 The original asbestos cement was a flat sheet about cm x 40 cm forerunner of the many sizes and types of asbestos cement products now made and used all AM over the world - Manufacture began first in Austria then in 1903 in RICHLAND Switzerland followed by Belgium in 1905. Also prominent in the history of asbestos cement an Italian engineer named Mazza He met Hatschek and - contributed greatly to the development of suitable production equipment for asbestos cement He also COM ON developed a process for the production of high pressure asbestos cement pipes Asbestos cement pressure pipe manufacturers still use his basic method Another PLEAS process for pipes was developed by Alessardo Magnani This uses a revolving metal mandrel on to which is fed a thick slurry a method still widely used today for - asbestos cement pipes Magnani is also known as the designer of the first machine for the continuous production of corrugated asbestos cement sheets 203CP41759 Apart from asbestos cement there was also rapid development in this period in other asbestos products Asbestos textiles were used in packings for steam engines boiler insulation mattresses conveyor 2023CP401759 belting steam pipe jointing materials and protective clothing In the first decade of the 20th century woven asbestos cloth was used as a basis for brake linings and clutch facings on motor cars commercial vehicles and mechanised military transport Before the discovery in Canada in 1878. Italy was regarded as the and main producer of asbestos and many textile factories factories wove asbestos as a sideline Cape Group expansion As these and other new asbestos products appeared demand for raw materials increased the Cape Group there was steady expansion in output from the mines and at the same time the Group extended its original policy of being both a raw material supplier and a specialist manufacturer Today the Group is an international organisation engaged not only in mining and supplying asbestos fibres but in manufacturing asbestos and other products for use in building shipbuilding vehicle manufacture servicing and insulation applications throughout industry 670094 t Mining and Milling Occurrence Most of the world's supply of Amosite and Crocidolite asbestos comes from Southern Africa The deposits occur in the banded ironstone beds of the Transvaal system of rocks which are exposed in a long arc stretching northwards from the Orange River in Cape Province to Botswana and thence eastwards to the Olifants River area of Eastern Transvaal The most important Crocidolite mines are situated along a 300 mile line of hills in the Cape Province extending from Koegas in the south to Pomfret in the north Crocidolite from these mines is known as Cape Blue to distinguish it from Transvaal Blue taken from the much smaller deposits in the Malips River area of Eastern Transvaal Transvaal Blue is not a pure Grocidolite and has intergrowths of both Amosite and silica Amosite occurs in Eastern Transvaal the mines being located at Penge Kromellenboog and Weltevreden Other fibrous Amphiboles Tremolite Actinolite and Anthophyllite art found in relatively limited quantities in many parts of the world Their low tensile strength inite cheir comme cial importance in the asbestos industry Mining The ming ming methods employed for Amosite and Blue ae rely different from those employed for Stile Chrysotile occurs in soft serpentine rocks as fibre seams close to the surface and massive in nature Such deposits can be mined by open cast or block caving methods The narrow rich seams of amphibole fibre run deep into the ground often at inclines varying from the horizontal to almost vertical The angle of dip determines the mining method but some mines are currently operating at 300 metres below surface ELCTRONIALY ELECTRONICALY ELECTRONICAL Y SOUTH WEST AFRICA FILED peu kes .Penge MOZAMBIQUE Weltevreden ; 2023 Weltevreden \ 2 bes Johannesburg Kromellenboog Oct Johannesburg TRANSVAAL TRANSVAAL Pomfret ^' TRANSVAAL - Fan ea r 18 10:18 ace Koegas Siea? Westerberg CAPE PROVINCE AM Asbestos Mines Blue Asbestos Mines RICHLAND Location of Cape's Amosite and Blue Asbestos Minos Milling The mined rock containing Amosite or Crocidolite is hoisted to the surface and separated into fractions initially for various drying crushing and sorting PLEAS operations according to size Because the ironstone - rock is so hard and abrasive it is essential to remove as much as possible before attempting to extract the fibre 203CP4 1 The product is then fed into fiberisers for release of the asbestos which is then separated from dust rock particles and stones After further processing the separated fibre is cleaned in special gritting and and dusting equipment There is then a final grading and air washing after which the fibre is pressure packed into bags ready for sale Classification Chart of the Asbestos Minerals I Chrysotile White Asbestos 3MgO 2SIO 2H 2H O O Asbestos Fibrous Amphiboles Amosite 5.5FeO 1.5MgO 8SIO H O | | Anthophyllite Crocidolite |" 7MgO 8SiO2 H O Blue Asbestos Na Fe 3FeO 8SIO Tremolite 2CaO 5MgO 8SIO H O Actinolite 2CaO 4MgO FeO 8SiO2 ELECTRONICAL Y ELCTRONIAY Physical and Chemical Properties FILED - Structure The basic structural unit of Amphibole asbestos is a double silica chain each chain having four silica tetrahedra in its cross sectional view Fig 1 The two parallel chains are separated by a band of cations which in the various forms of Amphibole asbestos include magnesium calcium iron and sodium together with other elements in minor quantities In Amosite and Crocidolite these cations are mainly composed of ferrous and ferric iron The cross section of a microscopic fibre of Amphibole asbestos comprises a uniform stacked arrangement of these structural units Fig ) The strong cross linking in this structure leads to considerable rigidity in the fibre and as a result small fibres of Amosite and Crocidolite are always straight while larger fibres possess marked resilience in the axial direction This is the main reason why these types 2023 Oct 18 10:18 of fibres provide much more bulk volume in both the dry state and in aqueous suspensions than Chrysotile AM The route of the preferred cleavage th Ae - line amphibole structure - in Fig )sei oe! resulting fibre surface is formed substantially by suica RICHLAND tetrahedra It is the presence of this surface which is responsible for the relatively high chemical stability of Amosite and Crocidolite and for the spec surface - properties of Amphibole fibres general Amphibole COM ON Fig 2 shows a schematic structure of asbestos This is entirely different from the structure and accounts for the difenosa difenosa Chrysotile Amphibole SUG in of these fibres Note that the i ..ccr Chrysotile fibre consists of an assline hydroxide layer PLEAS - i & Bla . 203CP41759 \e HYDROXIDE % fi P 5 MAGNESIUMMAGNESIUM rea wo \ SANAwe*. MAGNESIIUMONS 203CP401759 r \ ao ? fs) \ Gis o i <F oe HYDROXIDE HYDROXIDE HYDROHYXDROIXIDEDE MAGNESIUM IONS g 1 CELL UNIT IONS SILICA A SILICA IONS Schematic 1. Amphibole line AA represents diagram of the crystal indicatingthe unitcell represents the edge of the plane along which the fibres fibres will split to structure of an based oXn Si OH 2- preferred cleavage form even smaller fibres structure of a Chrysotile fibre formed of several scrolls individualcrystallites Each scroll is formed from closely closely connected double layer having magnesium hydroxide units on its external face and silica units on its inner face The details of a small section of the scroll show the structure of the double layer and of the unit cell based on Mg SiOs OH Stereoscan photograph of Chrysotilc Fibre magnification X4500 . ical Properties hain silicate structure of Amphibole asbestos has igh intrinsic strength attributable to the bond etween adjacent silica tetrahedra Crocidolite from certain deposits has the highest known tensile strength at 35,000 cmof any mineral fibre Amosite has a lower tensile strength of 25,000 cm Table 2 summarises the most important of the physical and chemical properties of the main varieties Table 2 . of asbestos In comparing the Amphibole fibres with large Chrysotile fibre it will be seen that certain tempera differences exist notably in density fusion ture surface charge and optical properties Some ce. these properties are important in the identification different types of asbestos while surface char characteristics are of asbestos technology considerable charimportance Physical and Chemical Properties of the Asbestos Minerals 6SZ Property Colour Natural Fibre Length Fibre Diameter micron Crystal System Amosite Ash Grey 3 to 70 mm 0.1 to Monoclinic Crocidolite 3to 70 mm to 1 MMonooclninoic clinic Chrysotile 1 to 40 mm 0.01 to 1 Monoclinic and Orthorhombic Occurrance Optical Properties Refractive Index Specific Specific Gravity Hardness Hardness Mohs scale Specific Heat gm 2 Tensile Strength cm Youngs Modulus cm Heat resistance % residual strength at Banded ironstones ironstones Biaxial positive extinction parallel 1.657-1.898 pleochroic 5.5-6.0 5.5-6.0 0.193 25,000 1.65 x 10 100 7 Bandeo ironstones Biaxial positive or negative extinction parallel 1.685-1.698 pleochroic 3.37 35.000 1.9 10 100 38 18 Serpentines Blaxial positive extinction paralle 1.50-1.55 pleochroic 2.55 2.55 2.55 2.5-4.0 31.000 1.6 ^ 15 0 100 100 16 Fusion point C Surface Charge 1,100 negative negative positive positive positive positive positive ELECTRONICAL Y Table 3 Chemical Compositions of the Asbestos Minerals SiO silica Typical data Amosite 49.7 Crocidolite 50.9 ELCTRONIAY Chrysotile 38.9 FeO ferrous oxide Fe O 37 ferric oxide alO umina 39.7 trace 0.4 20.5 17.45 17.45 2.0 FILED 1.6 3.1 - CaO calcium oxide MgO magnesium oxide 1.0 1.5 0.9 6.4 1.0 40.0 2023 MnO manganese oxide Na sodium oxide K.O. potassium oxide 0.2 0.1 0.6 0.05 6.2 0.2 0.1 Oct 0.1 18 0.2 H wOater CO carbon dioxide 1.8 0.1 100.0 2.0 0.2 100.0 10:18 12.6 0.5 AM 100.0 - Chemical Properties The behaviour of asbestos in water is determined by the surface charge The charge on Amosite and Crocidolite is slightly negative while that on Chrysotile is more strongly positive Because of their low surface charge Amphibole type fibres interlock together in water to give an open lattice work of fibres having high bulk volume and acting as filter aids These properties are quite different from those of more strongly charged fibres which by mutual repulsion slide over each other to form a compact mass of small volume Amosite and Crocidolite are thus complementary to Chrysotile and have particular importance in extending fibrous bulk and improving drainage rates in wet systems containing Chrysotile Chemical Properties The chemical compositions of Amosite and Crocidolite given in Table 3 show that these forms of asbestos contain up to 40 per cent of combined ferrous and ferric iron as oxides and up to 50 per cent of combined silica Since they contain oxidisable iron both Amosite and Crocidolite turn reddish brown when they are heated Certain types of Amosite and Crocidolite from surface deposits have similarly suffered oxidation by natural weathering during many millions of years and such fibres contain products of weathering which diminish the properties of the asbestos It is only the Amosite and Crocidolite fibres mined in deep subsurface deposits which possess all the properties described in these pages Asbestos fibres no matter what types of asbestos cannot be regarded as being completely thermally resistant All varieties of asbestos break down progres- sively through a series of internal reactions which may begin as low as 200 reaching finality at about 800 They lead to a conversion of the composition and structure to simpler silicates and oxides and are accompanied by a loss in strength see Table 2 Although Amosite and Crocidolite break down in this RICHLAND way when heated it does not mean that their propertie - as heat insulators are diminished Vect COM ON compounded partially or wholly into heat insula materials Amosite and Crocidolite fibres retain form though they are internally changed at hi peratures They possess ablative properties in ti PLEAS products of decomposition at a hot surfacfeo poorly conductive layer which provides protection - the succeeding layers of insulation Since the surfaces of amphibole asbestos are substan- tially formed of silica units they are relatively inert 203CP41759 and possess considerable resistance to decomposition by chemical reagents Crocidolite in particular has high resistance to acids see Fig 3 and combines the advantages of high chemical resistance with high reinforcing characteristics This type of asbestos is par- 203CP401759 ticularly useful in applications requiring both reinforce- ment and corrosion resistance 60 50 40 30 20 Loss Weight % 4 Fig 3 Typical acid resistance curves for different types of asbestos ELECTRONICALLY ELCTRONIAY TheTechnology ELECTRONICALY of Amosite and Crocidolite FILED FILED - 2023 Oct 18 Fibro L gth While complete segregation into precise length gradings is not possible for any type of asbestos the fibres of Amosite and Crocidolite are separated into different grades by length classifiers during the milling process The fibre lengun characteristics of Amosite and Crocido- Nite contribute ties of these for way to the insulating properpre length produces the fibrous bulk which ential to good thermal insulating materials Tests hav nown that even the shortest fibres in any grade will play a part in providing valuable rein- forcement in cement based and plastic materials and in developing the cellular structure that is important in thermal insulation Fibre Diameter Fibre diameter is also important in determining the efficient application of asbestos fibres Fibre diameter is an expression of degree of fiberisation that is the degree to which the asbestos is split down to fine fibres ideally approaching 1 micron in diameter The thermal insulating properties of Amosite are as much dependent on fibre diameter as on fibre length Amosite can be milled to produce fine fibres with minimal reduction of length thus producing a fibrous mass of very high bulk The reinforcing properties of Amosite and Crocidolite are also dependent on fibre diameter maximum reinforcement being obtained from the finest undamaged fibres It is for this reason that the importance of good techniques for fiberisation is stressed in a later section Page 13 10:18 Surface Properties and Drainage AM RICH In any manufacturing process employing a wet system in which asbestos fibres are used the surface proper ties of the fibres have a vital effect In the asbestos cement system Chrysotile fibres tend to coagulate together while Amosite and Crocidolite fibres form a uniform dispersion Aqueous suspensions of cement_ and Chrysotile drain with difficulty while simila suspensions of cement with Amosite or Crocidolit^' drain as much as three or more times as rapidly as those with Chrysotile Both these extremes aren undesirable and therefore blends of Chrysotile with the amphibole fibres provide a means of obtaining an optimum balance Up to 20 per cent of Amosite is required in a blend with Chrysotile to assist drainatgheen without interfering with the essential plasticity of furnish in asbestos cement sheet manufacture In 3023CP4001759 3023CP40 1759 Stereoscan electron micrograph of Amosite reinforcement in asbestos cement Magnification x 2100 3023CP401759 Tensile Strength Crocidolite asbestos has the highest tensile strength of any known mineral fibre and it follows that in composite materials such as asbestos cement and reinforced plastics Crocidolite imparts the highest reinforcement among all forms of asbestos The mean tensile strength of Amosite is about 70 per cent that of Crocidolite and its reinforcing strength is proportionally lower 7 ELECTRONICAL Y EFLCITRLONIEADY FILED - 2023 Oct 18 10:18 AM - RIC-HLAND COMON Measurement of the tensile strength of asbestos PLEAS - production of asbestos cement pressure pipes up to 40 per cent of Crocidolite Crocidolite with Amosite- in the blend with Chrysotile is required not only to assist drainage in the manufacture of thick walled pipes but to provide the reinforcement needed in medium and large diameter pipes Amosite and Crocidolite are thus complementary to Chrysotile in the asbestos cement process Their surface properties are such that the fibres perform as filtration aids and also assist in dispersing the Chyrso- tile fibres more effectively The drainage properties of Amosite are also important in other systems particularly those concerned with the manufacture of insulation products In the manufacture of thermal insulation and insulating boards based on calcium silicate the drainage rate of raw materials suspension either on Hatschek machines or in press forming methods is maximised by the use of high proportions of Amosite in the furnish The surface properties of Amosite and Crocidolite are also important in the field of reinforced plastics Since the surface of Amphibole types of asbestos is nearly polar it follows that these will have a greater affinity for the less polar resin systems Amosite and Crocidolite are thus more compatible with polyhydrocarbon systems such as polythene and polypropylene than with polyester and phenolic systems This does not in any way preclude their use with the latter materials where their known reinforcing effect is very high Thermal Insulation 203CP41759 Amosite asbestos by virtue of its fibre length its fine fibre diameter its harshness or stiffness and its surface properties will when suitably processed give a fibrous mass of high bulk volume both as a dry product and as 203CP401759 a suspension in water When the dry fibrous mass is compressed it encloses air distributed in tiny pockets throughout its entire bulk Suspensions of Amosite in water with such other materials as are essential for the manufacture of calcium silicate thermal insulation or fire resisting boards will similarly after complete processing and drying contain these well distributed tiny voids of air Modern high temperature thermal insulations are made in a density range from 0.2 to 0.3 cmto provide a porous structure and maximum thermal efficiency Heat transfer by convection can only occur where air movement through the insulation is possible Any such movement is controlled by the fine fibrous nature of Amosite which simply restricts convection by virtue of the high flow resistance of the fibrous mass Radiation losses in a thermal insulation are controlled by the opacity to infra wavelengths of the solid phase of the insulation The fine fibres of Amosite asbestos provide such opaque barriers and so assist in keeping radiation losses to a minimum Mino Amosite of Penge including tears nmi ELECTRONICAL Y ELCTRONIAY Quality Testing FILED FILED - 2023 Oct Quality control of Amosite and Crocidolite at all stages 18 from the mine refineries to Central Quality Control 10:18 Laboratory Research Laboratory and ultimately to Works and Plant Control Laboratories is governed by the recommended techniques given in the manual of AM Test Methods for Blue and Amosite Asbestos pub- - lished by Cape Asbestos Fibres Ltd. The most important RICHLAND tests for Amphibole asbestos are summarised in the following paragraphs - Fibre Length COM ON This is determined by a length classification test such as Quebec Standard Asbestos Test the Rotap Test and the Bauer McNett Classification test The first two of these are dry screening tests in which a standard PLEAS weight of fibre is shaken on a stack of screens of diminishing mesh size - The Bauer McNett Test is one of the most useful classi- fication tests for any form of asbestos This is a wet classification test by which a sample of fibre is washed 203CP41759 through a series of screens of diminishing mesh size The fractions of fibre collected by each screen are dried and weighed and expressed as percentages of the test sample The largest screen in the Bauer McNett is size 4 mesh The fraction collected on this screen can McNett Machine ultimately be assessed by hand sorting to give an Quebec Standard Asbestos Test Machine fully enclosed and 2023CP401759 account of the upper length range of the sample tested dust exhausted Fibre Diameter This is determined indirectly by measuring the apparent surface area of the asbestos sample the results being expressed in terms of cmThe surface area of fibrous materials is approximately proportional to the inverse ratio of fibre diameter in other words the greater the surface area the smaller will be the fibre diameter The surface area of Amphibole asbestos is most easily measured by an air permeability method A plug of asbestos of standardised weight volume and porosity is compressed in a cylindrical steel cell perforated at both ends A standard volume of air is then drawn through the cell and the time taken to do this is measured The Rigden Air Permeability Apparatus is normally used for this test Taken together the Surface Area Test and the Bauer McNett Classification Test are the two most important means of assessing the properties of Amosite and Crocidolite fibres Reinforcement Tests On a laboratory scale the reinforcing strength of asbestos fibre in asbestos composites is determined in the following way An asbestos cake is made by filtration of the solid materials from a thoroughly mixed suspension of 1 part of asbestos fibre to 9 parts of cement in water The suspension is filtered on a suitable filter box to form a disc or rectangular pad the component weights being chosen so that a vi td..dthickness of about 6 mm is achieved The cake is then compressed in a mould so designed that the finished density of the cake will be about 1.6 cm The cake is then cured and tested for flexural strength by three point loading in a standard test machine The modulus of rupture is then determined from the loading and the dimensions of the test jig and is corrected by proportionation to an exact density of 1.6 cmThe reinforcing strengths of all types of asbestos can then be compared in terms of a standard weight of asbestos in the mixture and at a standard density of product Hounsfield Tensometer Elutriation Test In another type of classification test the asbestos fibre is elutriated in rising columns of water The elutriation technique separates fibres on the basis of fibre diameter This technique enables the crude spicules to be separated from the open fibre in any sample and therefore gives a measure of the conversion of crude fibre to useful open fibre after processing 11 Elutriator Wet Volume and Filtration Tests The object of these tests is to provide data on the properties of asbestos fibres in an asbestos cement system under conditions which as far as possible are intended to resemble those in the mixing vessels and vats and on the felts of the asbestos cement machine Wet volume or buoyancy tests when correlated with machine running conditions provide a guide to the stability and homogeneity of asbestos cement slurries fisettling rates of solids in such slurries and consequently their response to the efficiency of available wet mixing vessels @ the bulk volume of pick up at sieve cylinders and consequently the density of the film transferred to the felt Similarly filtration tests provide a guide to & drainage rates at sieve cylinders f iltration rates of films on machine felts The standard method of test for both wet volume and filtration requires an asbestos cement slurry to be made with a solids content not greater than % the solids having an asbestos cement ratio of 9 The wet bulk volume or buoyancy of asbestos cement mixes is measured by suspending a fixed weight of the standardised mix in a fixed volume of water in a measuring cylinder The suspension is thoroughly mixed and then allowed to stand for thirty minutes when the volume of settled solids is measured The filtration time is measured on a similar suspension of asbestos and cement in water by filtering it under standard conditions through a suitable filter base The time taken for the filtration of a fixed volume of the suspension is a measure of the filtration characteristics of the fibre Filtration Testing Testing Apparatus Colourmeter Ancillary Quality Tests The laboratory of Cape Asbestos Fibres Ltd. uses additional tests to assess the quality of Amosite and Crocidolite asbestos and these include Thermal Analysis DTA and TGA to determine the effect of heat on asbestos fibres Infra Red Analysis for rapid identification Chemical Analysis in the evaluation of asbestos ores Colour Testing in the rapid assessment of purity Tensile Tests for the determination of absolute tensile strength of asbestos fibres Infrared Spectrometer ELECTRONICAL Y EFLCITRLONIEADY FILED - 2023 Oct 18 10:18 AM - RICH- LAND COMON PLEAS - 203CP41759 12 Fiberising fiberising of asbestos 13 All forms of asbestos differ in texture To describe this ELECTRONICALLY fundamental property of asbestos which cannot be ELECTRONICAL Y stated in quantitative terms the designations harsh ELCTRONIAY harsh and soft are universally adopted Amosite is a harsh asbestos with resilient and spiky fibres Crocidolite also has resilient fibres but being softer than Amosite is described as harsh Chrysotile fibres from their many different deposits vary from semi- FILED harsh to soft types These differences in texture have an important bearing - 2023 on the choice of processing machinery which will be used to fiberise asbestos to the degree required in its 2023 Oct many applications The mine refineries supply Amosite Oct and Crocidolite in the crude and processedOct form in press packed bags to reduce freight costs to a 18 minimum Before the asbestos can be applied to 10:18 manufacturing process it therefore has to be fiberised 10:18 AM to the degree appropriate to the process and by the best AM means available to manufacturers The following summary outlines the effectiveness of RICHLAND the various types of processing machinery currentlRyICHLAND available for fiberisation of Amosite and RICHLAND Crocidolite - Wet Fiberisation COMON Rod Mills Amosite and Crocidolite in blends with Chrysotile are processed in the rod mill with the addition of waterU using the same loading of rods as for Chrysotile alone A If Amosite alone is to be processed in the rod mill then a much lighter loading of rods will be required Whereas processing by rod mill increases the intrinsic a reinforc- ing value of Chrysotile above that obtained by dry_ fiberising methods the reinforcing value of Amossaimteed and Crocidolite is found to be the same at the degree of fiberisation whether the processing be by rod mill or by dry fiberising mill At the same time rod mills do not have any abnormal effect on the drainage- properties of Amosite and Crocidolite 759 Kollargangs Semi fiberised Amosite and Crocidolite grades are recommended wherever fibre processing by Kollargang is operated Amosite and Crocidolite should be fed to the Kollargang with Chrysotile at the beginning of the crushing cycle and will require the addition of water up to 50 per cent of the total weight of fibre feed Turbo Mixers and disintegrators These machines which operate on a water borne suspension of asbestos will fiberise both Amosite and Crocidolite The time cycle of wet disintegrators of these types is usually not more than 15 minutes and the degree of opening which can be achieved with Amosite and Crocidolite in this time is limited Semifiberised grades of these fibres are therefore recommended where turbo mixers and disintegrators are the main means of fibre processing Hydropulpers These are effective wet disintegrators and have the advantage that fiberisation of asbestos and the mixing with other raw materials may be done in one vessel fiberised Amosite and Crocidolite should be fed to the hydropulper with the total water charge and processed in the hydropulper for not more than five minutes before addition of other raw materials Mixing is usually complete after a further five minutes Dry Fiberisation Dry fiberisation machines have the advantage of providing a wide range of degrees of fiberisation and a product which being dry can be tested for fiberising effect by measurement of its surface area and by classification tests This is not so with wet fiberisers where it is difficult or even impossible to retrieve the product in a suitable form for testing In general a much greater degree of product control can be exercised when fiberising asbestos by dry methods than by wet methods Hammer Mills with Screens In this type of mill the asbestos is fed through the centre of the mill casing and is disintegrated by impact with high speed rotating hammers The exit port is tangential and is covered by a screen or grating The asbestos fibre cannot leave the mill until its length is reduced to a size compatible with the apertures at the exit Amosite and Crocidolite may be fiberised in these mills but satisfactory degrees of fiberisation are attained only at the expense of important fibre lengths This type of mill is recommended therefore for short grades of Amosite and Crocidolite Hammer Mills without Screens These mills normally have a disc type impeller with radiating beater arms Fiberisation takes place by impact of the asbestos against a circumferential liner in the mill casing The exit port of the mill has a variable orifice by which the dwell time of the material in the mill is controlled Decrease of the orifice increases the dwell time and increases the degree of fiberisation This type of mill is especially efficient with Amosite and Crocidolite asbestos since is offers a wide range of degrees of fiberisation with minimum loss of length for all medium and short grades See photo of Varyiser mill Willow Mills These are fan type disintegrators with both selfinduced and separately induced air flow They are recommended for the processing of long Crocidolite for textile applications where an initial degree of opening is required Other grades of Amosite and Crocidolite can effectively be fiberised in a willow mill with minimum loss of length but may require more than one pass through the mill to achieve the required degree of fiberisation Attrition Mills ELECTRONICAL Y This type of mill has a disc impeller carrying a number ELCTRONIAY of pins or anvils on its plane surface which intermesh with similar pins or anvils on the plane surface of the mill casing This type of mill is suitable for the fiberisa- tion of softer types of asbestos It is recommended for the processing of short grades of Amosite and Crocido- FILED lite but may induce considerable shortening in length of the medium and long grades of these forms of - asbestos 2023 Recommended degrees of Oct fiberisation of Amosite and 18 Crocidolite in various applica 10:18 Degree of AM fiberisation as - Surface Area Range in crude and crude grades Range in processed grades Amosite in thermal insulation Amosite in insulation boards Amosite in spray insulation gm RICHLAND - 1,500 to 6,000 8,000 to 10,000 COMON 12,000 8,000 10.000 Amosite in asbestos cement Crocidolite in asbestos cement Amosite and Crocidolite in 9,000 11,000 PLEAS - bitumen compounds - 8 10,000 Amosite in catalyst supports Amosite in packings Amosite and Crocidolite in 14 70 8,000 to 9,000 plastics Crocidolite in textiles cards 10,000 to 13,000 4,000 203CP41759 A Varyiser mill showing rotor in position 14 Table 4 General Classification Extra Long Long Medium Short Se Table 5 : Amosite Grades Penge Mine Grade McNett Weltevreden Mine | Kromel- | lenboog Mine 14-100 +M |M % |% Surface Area cm ELCTRONIFIALELDY FILED Main Use FILED FILED 2023 2023 2023 D.11 M S11 S22 22 33 S33 S44 oo W3 SW GW 70 | 20 K3 20 | 26 62 | 26 SK 59 | 2015 40 35 GK RK 6605 46 | 35 33 | 40 18 | 50 21 | 47 10 | 55 . 3000 3500 3500 4000 8500 5500 8500 8500 6000 7000 Moulded Insulation Oct Oct Moulded Insulation 18 18 General Insulation and Board Products Asbestos Cement Pressure Pipes 10:18 10:18 PT Insulating and 3 + Fire Resisting Boards Refractory Tiles -RICHLAND Refractory -RICHLAND -RICHLAND and Fire Resisting Boards -RICHLAND Refractory Tiles and Asbestos Cement -RICHLAND Asbestos Cement Sheets and -RICHLAND -RICHLAND Moulded Products Plastic Reinforcement COMMON COMMON COMMON COMMON : above table are typical test results and are not to be used as specifications - COMMON PLEAS PLEAS Le PLEAS PLEAS PLEAS Crocidolite Grades CASE CASE CASE CASE # 2023CP4001759 2023CP4001759 2023CP4001759 2023CP4001759 2023CP4001759 2023CP4001759 2023CP40 1759 2023CP4001759 2023CP401759 2023CP4001759 , General Classification | ; Grade Grade McNett Test aoe Surface Area | + 14M -100M Surface cm Main Main Use Long DO - +7 1000 Asbestos textiles DO 8 +7 2000 Felts for reinforced plastics Medium Short S 67 S80 66003.83 2S 66003.83 H 66003.83 H80 66003.83 _ C10 66003.83 WDS 66003.83 20237 6500 20237 10,000 Asbestos cement pressure pipes 20237 7000 Asbestos 20237 8000 43 10,000 cement sheets 7 14,000 Asbestos paper 43 9000 Asbestos cement sheets The values shown in the above table are typical test results and are not to be used as specifications 15 FIELCLTRONEIADY es Amosite Insulation This type of insulation is made from 60 to 85 per cent Amosite together with inert fillers such as diatomaceous earth bonded with an inert adhesive sodium silicate The process of manufacture is semi and relies completely on the high dry bulk volume of Therised Amosite to achieve a low density product The site requires fiberising to a surface area of 12,000 n for this process The end product has a density ne of 0.2 to 0.3 cmits thermal conductivity imately 0.2 ^ 10-3 cm at s heat resistance as an insulation is good es in the range 650 to 800 depending Jed grades of Amosite S11 Silicate Insulation aterials based on autoclaved calcium 10 15 per cent Amosite which in this s mainly as a reinforcing fibre having at Insulating and temperature resistant products are made by moulding the sing both vacuum and pressure from a materials containing lime silica and e conditions the rapid drainage proper- essential for the achievement of . rates from the moulding equipment e products is in the range 0.2 to 0.3 al conductivity K at 550 hot s approximately 0.2 ^ 10-3 cm C cm Their heat resistance can be extended to 1,000 at a product density of 0.3 cm Amosite is important in this type of insulation as a reinforcement for the otherwise fragile calcium silicate preserving the integrity and reducing the shrinkage of the insulation at high temperatures Recommended grades of Amosite M 11 W3 K3 Asbestos Products Asbestos products are essentially incom- bustible weather proof materials for external use on buildings Typically asbestos sheets and the products made from them have an intrinsic modulus of rupture between 160 and 200 cmat densities between 1.55 and 1.65 cmThe basic material in flat sheet form is manufactured predominantly on Hatschek board machines These products contain about 12.5 per cent asbestos mainly Chrysotile Amosite is widely used in the asbestos process in proportions between 10 and 30 per cent of the total asbestos content and provides a number of advantages Primarily it is a filter aid and increases the drainage rate of the asbestos mix at the machine by up to 10 per cent of that attributable to Chrysotile blends alone It also improves the wet strength of the sheet leaving the machine In terms of reinforcing strength short Amosite fibre may be regarded as equivalent to all grade 5 Chrysotiles and medium length Amosite as equivalent to some grade 4 Chrysotiles Where lower grades of Chrysotile pre- dominate in the manufacture of asbestos Amosite is advantageous in the control of product density which otherwise may be considerably higher 17 Asbestos cement roofing components than the optimum thus giving rise to high raw material consumption Recommended grades of Amosite 22 65 33 S33 GW GK S44 ELECTRONICALLY ELCTRONIAY FILED - 2023 Oct 18 10:18 AM - Asbestos cement pressure pipes during installation Asbestos Pressure Pipes Asbestos pressure pipes are manufactured to withstand hydraulic test pressures up to 47 atm and working pressures up to half this value They normally contain 15 to 20 per cent of asbestos fibre The high hydraulic standards of pressure pipes demand high hoop tensile strengths in the barrel of the pipes and a high degree of orientation of reinforcing fibres in the circumferential direction Crocidolite fibre provides both the reinforcing strength and length to satisfy these standards Typical fibre blends for asbestos pressure pipes contain 20 to 40 per cent Crocidolite and 80 to 60 per cent medium length Chrysotile Good drainage of the wet asbestos mix is essential at all stages in the manufacture of pressure pipe from the sieve cylinder to the felt and finally at the making mandrel itself At the latter stage drainage is inhibited by the density of the pipe wall up to 2.0 cmin the finished product and also by the thickness of the wall which may be up to 50 mm Drainage performance in this process is controlled by the Crocidolite fibre also by the incorporation of medium length Amosite in the fibre blend A recommended blend of long standing and frequent use includes 30 per cent Crocidolite 10 per cent Amosite and 60 per cent Chrysotile Recommended grades of Crocidolite S S80 2S Recommended grades of Amosite 11 S22 SW 65 RICH- LAND COM ON Bulkheads and linings of Marinite fire ri veneered with laminate plastic being Queen Elizabeth 2 PLEAS - Insulating and Fire Resisting Boards Insulation boards possess properties way between 203CP41759 thermal insulation products and asbestos sheets They are fireproof incombustible both thermal insulating and sound insulating and are manufactured for use as internal linings in buildings and ships Their 2023CP401759 typical properties are density 0.7 cmthermal con- ductivity K at ambient temperatures 0.3 ^ 10 cal cm cm mean modulus of rupture 125 cm This type of board contains up to 40 per cent of Amosite in a calcium silicate matrix the latter being formed from lime and silica by direct synthesis The raw materials mix is formed into the boards by filter mould- ing under pressuroer on a Hatschek or Magnani type board machine Insulation boards rely on Amosite to provide adequately low densities to allow for rapid drainage in the manufacturing stage of what is normally a high production rate board to give high reinforcing strength for a relatively low density and to give the board integrity and low shrinkage in specified fire rating tests These boards are unaffected by wet conditions and will not support mould growth The world is becoming very much more conscious of loss caused by fire and more and more Amosite asbestos is being used in the manufacture of fire resisting boards Recommended grades of Amosite 11 22 SW SK S22 S33 S33 GW GK 18 ELECTRONICAL Y ELECTRONICAL Y ELCTRONIAY FILED - 2023 Oct 18 RICHLAND RICHLAND - COM ON Battery box made from Asbestos composition PLEAS - Sprayed Insulation Sprayed insulation is a means of placing an insulating layer on uniform and otherwise inaccessible surfaces though it is frequently and equally well used to cover flat surfaces It has both thermal and acoustic insulating properties and normally has an asbestos content exceeding 60 per cent Spray insulation consists of a wet asbestos mixture prepared on site and applied to the working surface through a pressurized spray gun The adhesion and stability of the wet spray is governed by its water content and plasticity and the insulation properties of the finished surface are determined by the bulk volume of the asbestos used Amosite grades of various lengths depending on the | type of gunning machinery are used in spray compounding Blends of Amosite and Chrysotile provide respectively the essential insulation bulk and plasticity Amosite in addition giving a means of control of the water content of the compound by virtue of its low water absorption properties Recommended grades of Amosite M. 11 W3 K3 S33 S33 Short grades of Amosite are recommended where a heavier density compound is needed for fire protection Recommended grades 44 and 6605 19 Bitumen Compounds CASE This heading covers a number of applications including motor vehicle battery boxes water cisterns and pitch fibre pipes The manufacturing process invariable requires a hot molten bitumen either as moulding battery mixture with asbestos in the manufacture of boxes and cisterns or for impregnation purposes in the pitch fibre pipe process Since bitumen contains phenolic and cresylic acids only the resisting types of asbestos Crocidolite and Amosite can be used in these applications In the finished product Crocidolite and Amosite fibre provide reinforcement but even more important is that these types of asbestos give stability to the product inhibiting creep and deformation at ambient temperatures up to 40 Amosite is used in proportions of up to 15 per cent as the reinforcing and stabilising fibre in water cisterns and pitch fibre pipes Crocidolite is the preferred asbestos fibre used in the manufacture of battery boxes since apart from its reinforcing value it has high resistance to attack by sulphuric acid and a low manganese content which is essential to avoid poisoning of the acid cell Amosite is sometimes used Recommended grades of Amosite for pitch fibre pipes M S11 W3 K3 S22 S22 for water cisterns S33 S33 GK GW Recommended Grade of Crocidolite for battery boxes H80 ELECTRONICAL Y EFLCITRLONIEADY FILED - 2023 Oct 18 10:18 AM - RICH- LAND COM ON Uphill teeming of alloy steel ingots from 135 ton ladle using Asbestos reinforced plastic pipe fittings moulds lined with refractory tiles PLEAS - Refractory Tiles In the process of casting high quality oxidised alloy steels in ingot moulds the cooling of the ingot causes a cavity to develop in the upper parts of the solidifying metal This cavitated portion of the ingot is removed in the subsequent ingot rolling process and as such constitutes wastage which is returned for remelt- ing To minimise this wastage ingot moulds are surmounted by a steel hot top lined with refractory tiles the purpose of which is to reduce the rate of heat loss at the top of the ingot and in turn to reduce cavity development The major refractory and insulating component of these tiles is silica sand to which is added an organic resin binder together with Amosite fibre as the reinforcing agent These tiles are made from the wet raw material mix by vacuum forming and Amosite is essential in the preservation of a uniform mixture and in minimising the drainage time on vacuum forming Amosite gives strength to the finished product and ensures its handlability Finally in the user stage at exposed temperatures near 1,500 Amosite fibre helps to preserve the integrity of the burnt tile by acting as a high temperature binder Recommended Grades of Amosite 22 S33 S33 Reinforced Plastics 203CP41759 The incorporation of Amosite and Crocidolite produces properties in reinforced plastics which are not found with glass fibre or Chrysotile Amosite and Crocidolite are not necessarily replacements for either of the latter materials but may be used in conjuction with them or in 203CP401759 their own right Amosite and Crocidolite are known to be compatible with all the well known resin systems such as polyester epoxide phenolic and polyhydrocarbon and form a fibre resin bond which can give advantages in strength and stiffness over comparable glass fibre resin bonds The major application for Crocidolite in such materials is in equipment manufactured for the chemical industry including corrosion resistant linings in pipe lines and storage vessels and corrosion resistant parts for pumps and mixers Shatter proof mouldings for application in the automotive industry include Amosite and Crocidolite in their composition and the ablative properties of Crocidolite reinforced phenolic resins have been utilised in rocket heat shields Recommended grades of Crocidolite A S H80 C10 Recommended grades of Amosite 22 65 RK S44 20 Catalyst Supports Low temperature catalytic reactions involving gaseous hydrocarbons require high surface area catalyst for maximum conversion efficiences Fully processed long fibred Amosite is recommended as a support for valuable catalysts in these applications In this form Amosite has a high absolute surface area approaching 4 ma high bulk volume of self supporting fibres an open texture with high porosity and penetration and is technically viable in any oxidising application up to temperatures of 300 Recommended Grades of Amosite S11 These grades require to be reprocessed for use as catalyst supports Packings and Jointings Packings joinings joinings and sealing compounds based on schorten fibres possess three features in common Dey must have a degree of resilience to permit ation of a perfect seal under high pressure hey must be resistant to heat and chemical , permit a wide range of usage Thirdly they high tensile strength to prevent material e high degree of resilience found in Amosite idolite makes these fibres generally unsuitable toi se 0 compressed rubber type sheeting for gaskets they - the essential properties to satisfy the other requiringen requiringen Their natural bulk volume and resilience impart the right degree of compressibility to the product They are heat resistant and have high intrinsic tensile strength thus imparting high reinforce- Pressure packed fibre ready for shipment * ment in flange gaskets and gland seals Crocidolite i# particular is chemical resistant and is special recommended for jointing materials in lines carrying hot acids and alkalis e) Recommended grades of Amosite S22 S33 Recommended grades of Crocidolite C for plaited CALLY woven packings S80 H80 CALLY FILED FILED FILED Asbestos Textiles FILED Long fibred Crocidolite has for many years been use in the manufacture of yarn and woven cloths When suitably processed it has an acceptable texture f carding spinning and weaving am Such textile products combine all the outstanding features of Crocidolite Crocidolite yarn and cloth hav high tensile strength high resistance to corrosive chemicals and vapours are heat resistant and incor bustible They have applications in the chemical industry as screen cloths cloths In the manufacture insulation gas filters and of reinforced plastics both the yarn and the cloth when suitably impregnated will produce materials having tensile strengths up 4,000 cmin finished products COMMON Recommended grade of Crocidolite C. COMMON Other Applications COMMON A few examples of other applications of Amphibole fibres are as follows PLEAS 1. Amosite millboard example in the surfacing PLEAS calender rolls used in plate glass manufacture PLEAS 2. Amosite compounds as plug and crack fillers CASE 3. Blue asbestos for diaphragms of electrolytic celle 4. Chemically resistant filters CASE 2023CP40 2023CP40 2023CP40 2023CP40 2023CP40 2023CP40 : ELECTRONICAL Y Cape Asbestos Group Technical Advisory Service ELCTRONIAY A comprehensive technical service is offered to users ELECTRONICALY Safety in handling Most countries have established regulations to ensure of Cape Amphibole fibres world wide Technical repre- the safety of workpeople employed in the asbestos sentatives in the field advise manufacturers on fibre selection and processing and they are backed by the work of the Fibre Research Laboratory at Uxbridge This modern laboratory block contains the latest equipment for the study of asbestos fibres and helps customers to obtain maximum economic use from them FILED industry In the United Kingdom the Asbestos Industry Regulations of 1931 have now been replaced by the - Asbestos Regulations 1969 which extend these precautions to all persons employed and are more 2023 specific in their control measures The precautions are based in the main the standards Oct Licensees of Cape processes also benefit from the recommended by the British Occupational Hygiene 18 extensive manufacturing experience of companies in the Cape Group which covers Asbestolux and other lightweight fire resisting boards asbestos flat and corrugated sheets insulation materials brake 10:18 Society and the new Regulations provide for exemption from their provisions where acceptable levels are not AM exceeded Where higher levels are unavoidable control by - linings and other products enclosure exhaust ventilation or other means RIC to users of many industrial materials are require Advice and information concerning safety and + in the use of asbestos is readily available from Asbestos Fibres Laboratory or from the Envir Control Committee of the Asbestosis Resear which has produced a number of advisory sat the guidance of asbestos users PLEAS - Commercial Information Tarriff Classifications 1. Brussels classification for asbestos and asbestos containing products is as follows Chapter 25.24 Asbestos not worked beyond beating cleaning and sorting Chapter 68.12 Asbestos cement articles Chapter 68.13 Asbestos reinforced with wire mesh Fabricated Asbestos and articles thereof worked carded dyed or spun Mixtures based on Asbestos alone or with magnesium carbonate Chapter 68.14 Friction materials for brakes 2. The standard International Trade classification for asbestos fibre is 276.4 Asbestos fibre can be imported into most countries free of duty but may be liable to internal taxes such as Turnover Tax and Added Value Taxes which vary from country to country and should always be checked by the Buyer before orders are placed 203CP41759 the ports is between 4 and 7 days depending upon the port used Transit times from the Crocidolite mines are between 6 and 14 days depending upon the port used Transit times to main markets throughout the world fall between 30 and 60 days according to the destination 203CP401759 Speed of delivery also depends upon the number of sailings available Detailed information on this subject can be provided by Cape Asbestos Fibres Packaging Amosite and Crocidolite is supplied packed in standard 50 kg impermeable bags Cape Fibres News News of developments in packaging and other _ improvements in service to customers together with date technical information appears in the quarterly Cape Fibres News available free on request Shipping Information Orders should be released before the 8th of the month if shipment is required the following month Advance notice of shipment is required because of the distance of the mines from the ports and the long transit times involved The transit time from the Amosite mines to 22 22 BARN 836 oN (AND - COMON PLEAS