Document qdKBNDeNqYgRkvJMpRDLD0j4E

E. 1. DU PONT DE NEMOURS & COMPANY KREBS PIGMENTS DEPARTMENT 256 VANDERPOOL STREET NEWARK, NEW JERSEY Serial No. Copy No. 103-44-64 - Y I Period Covered: NEWARK PLANT PIGMENT COLOR RESEARCH REPORT Final Report Plant Production and Development or A-l-D Semi Works Trial of Substitution of Disodium Phosphate & tomcniuia sulfate for Sec, Ammonium Phosphate. Mareh 1943 - June 1944, FILE: DATE: 210,,21 11/7/44 rg L / o . a / ................ NJ803B N37937 Serial So. KB-44-44 Copy So# f Copy to: #31 RusMrleel File S' - Research Office (210*21} : MS m aa*11 -#4 Imperial Chemical Industries, ltd# * s'# . a a J. ?. Belay, Wilmington (ICI vfcAM 4 - re - <s4""* BEWARE PLABT PIGMENT COLOB RESEARCH REPORT Final Report Title: Plant Production and Development of A-l-D Semi Works Trial of Substitution of Disodium Phosphate & Ammonium sulfate for Sec. Ammonium Phosphate# Period Covered: Rarch 1943 - June 1944# SUBMITTED Mi E* J. Hess C.J./JU4 APPROVED Six ?. Chalupski MTE SUBMITTED: 10/17/44 DATE ISSUED: 11/7/44 DUP050149723 a sssgaeacgsQt; this report Is & continuation of 18-43-30 and covers the reduction to plant practice of the K-1781 formula for *Impedexn {now coded A-l-S)* Sew standard A-l-D formulas, K-1904. and 1-2067. nave been written as a result of this work* Basalts on.. a total of thirty-six plant batches ere discussed in this report. A series of batches were also made in the Semi Vorks using modifications of K-1781 designed to give lower ingredient cost, this material is in process of evaluation by the faint laboratory. Plant manufacture of A-1-0 (K-1781 type) may be divided into the following categories! 1. Preliminary work and development of the plant formula In final fora. All of this work was done using the following equipment (part of the blue unit)i Vat 383 - lead lined wood vat, fitted with paddle agitator. This vat was used for slurrying the Bi-ammonium phosphate for delivery to the strike vat (Vat 2&L), Vat 391 or .ISA - lead lined scale tanks. Used for weighing and diluting caustic soda solution. Vat 381 - wood dilution vat. The copperas solution is weighed into this vat prior to strike* Vat. 281 - wood strike vat; capacity 8550 gallons! double puddle agitation, 17 RPM. Press? - 4iB wash pressj wood plates; rubber covered iron frames; frame capacity 2.05 cu.ft.; Labour electric pump. 2. Production in the yellow unit - a result of the taking over of f Vat 281 for the production of sine yellow. The following equipment was used! Vat348 - iron seal tank. Used for weighing and diluting caustic soda solution. 3Ca3LlSl,,,ai,.l:M - lead lined scale tanks. Used for weighing sad diluting (if necessary) the copperas solution prior to strike. y.qfr,.24? - wood strike vat; capacity 7650 gallons: turbine agitation, 100 R.P.I, Press 3 - 48" wash press; wood plates; rubber covered iron frames; frame capacity 2.05 cu.ft.; Labour electric pump* DUP050149724 3 3* trial promotion in the large blue unit strike vat* the equipment used follows: TmSl MI * lead lined wood vats paddle agitator* this vat was used for slurrying the Di-ammonium phosphate for delivery to the strike vat (fat 180} g|IJ4f - iron ale tank, Peed for weighing sad muting oaustlo soda solution, IllLlfl. * wood dilution vat, the copperas solution is weighed into ms vat prior to strike* Ssjyji - wood strike vat} capaoity 9920 gallons} double paddle agitation, SB,?*!,} no vest os vat, as shorn. On the basis of previous plant experience with an earlier formula, X-1S71, In the red unit (fat 200 - Press 21) a 15 mol batch sine (1-1/2 K-1781) was selected as representing the capacity of Press #7, A slight deoreasg (4$) in the caustic soda amount was the only deviation from -1701 used in this trial batch, ho difficulty was encountered during the strike, control tests and the appearance of the #Impdex* slurry were normal. Filtration of this batch was accomplished with consider able difficulty, however, and it was finally necessary to set up a stump press (10 frames) after the major portion of the batch (14 frames in 7 Press) had been processed. When the press was dumped four of the wooden plates were found to be cracked and had to be replaced. The most probable reason for the plate breakage was the excessive pressure built up in forc ing the press in order to filter the material in the scheduled pressing volume, It had been observed, however, that during the filtration the press frames filled dlscontinuously (probably due to the plugging up of the ports by the rapid settling of the plate-like particles) and this also may have caused breakage due to the variations la pressure produced on the thin wood plates. Because of the difficulty with filtration the batch sloe on subsequent manufacture was arbitrarily cut by 15$ and the pressing volume increased so that the resulting overall increase in pressing volume amounted to about 23-1/2$ The next 19 batches, made during the period of March to October, 1943, i the small blue unit (Tat 281) were based on this procedure. During the course of this production a number of varia tions from the basic process were tried most of them designed to facilitate production without affecting quality to any great extent. Among the changes used were: DUP050149725 X* Although it was known that high temperature drying tended to giro higher ferric iron and lower ammonia analyse# the necessity for using the Halted amount of dryer space available at its hipest efficiency aade It desirable to investigate the possibility of increasing the drying temperature of "Impede**. Optus examining available analytical data (the only basis for comparison of the quality of Individual batches now in use) " ' it was found that the three plant batches dried 43 hours at 14% showed m average figure of 8.31# ammonia and 5*26% \. ^ y ferric iron* these figures were wen. within the specification . limits of 1% ammonia minimum and 10# ferric iron maximum on Which shipments are based. It was decided, therefore, to dry a few/.plant batches at 180?. Satisfactory drying was accomplished . in &4*28 hours at this temperature and, although the ferric Iron content (the more significant of the specification figures) has varied over a considerable range (4*65# to 10.8$), twenty of the thirty-seven batches tested analysed between 7.4# and 8.9# ferric Iron and only two batches were slightly above the passable limit. The only suggestion that can be made as to the fceasan for the substandard results is over drying. This theory is based on laboratory experience which shows that by far the major portion of the ferric Iron present in the material is formed during the drying cycle (see 21-43-96) and any process that tends to release ammonia from the compound increases the tendency to form ferric iron. In any case, it is believed that 180F drying will give satisfactory results if carefully applied and the higher drying temperature is used in K-1904, the replacement formula for K-1781, The substandard material has been consumed slowly by mixing with satisfactory batches. 2* During the course of the early production in Vat 281 a number of batches were made using a strike temperature of 14F instead of the standard 150F. This was done on the request of the J operating department in order to save the Vinyon cloths then in use on the large Blue presses. A maximum temperature of 14F had been set up for pressing in order to conserve these heat sensitive press cloths. Bo difficulty with quality or processing was encountered although the first high ferric content sub standard batch was made at this time. The lower strike tempera ture was not believed to be responsible for this abnormal result, however* Subsequent experience with the 14F strike in Vat 247 (turbine agitation as compared with the paddle type used in Vat 281) Indicated that sense change in the material (probably smaller particle size) resulted in slow pressing. Excessive pressure was built up in the press thus causing considerable plate breakage* An attempt to straighten out the situation by cutting the batch 10# (11.5 mol batch) was not successful. Succeeding batches in Vat 247 were therefore made at 150F on both the 1X5 mol and 12*75 mol batch sizes. Pressing was normal with DU P050149726 5 either batch site* Although no definite reason can be given for the difference in the effect of the low temperature strike variable with the two strike vats if nap be concluded that strikes nap be made at 140f in Vet 2SL- without disadvantage in order to secure maximum filter cloth life tut the strike temperatures when using Vat 247 must be maintained within the specified range of 14S**X52?, J*. The K-1761 formula called for dilution of the caustlo soda solution with approximately as equal volume of water and then heating to the strike temperature (140 or 150?) before adding to the di-asmaonium phosphate* A number of batches made without diluting or heating the caustic soda were satisfactory in quality and it was decided to use this simplification regularly. It was found necessary, however, in subsequent production to shift ever from the lead lined seals tanks (Vat 351 or 356) to an iron scale tank (Vat 346) in weighing the caustic soda because of the slight corrosive effect of the strong alkali on the lead lining and because of the difficulty of scheduling these chromatesscale tanks for "Impedex* product ion. When Vat 346 was used in conjunction with strike Vat 24? it was found that conditions were such that the alkali must be diluted to about 350 gallons In order to obtain enough head for rapid delivery to the strike vat* So heating other than the slight temperature increase resulting from dilution of the alkali was used* 4. Both filtered and unfiltered copperas solutions have been used in making "Impedex* without any definite advantage in favor of the filtered type. However, there is probably some danger of going over the ferrle iron specification limit with the un entered material and the use of the clarified copperas solution is therefore recommended. 5. Elimination of the heating of the copperas solution to the strike temperature before addition had no effect on quality. The difficulty of controlling the temperature in the strike vat was definitely increased, however, because, under present con ditions, none of the "lapedex" strike vats are equipped with a thermometer. The considerable amount of ammonia evolved during the striking procedure makes it desirable to keep the number of samples dipped out for a temperature check to a minimum. The small amount of time saved in eliminating the heating of the copperas solution does not make up for the added disad vantage, therefor the use of cold copperas solution for the strike is not recommended. 6. Because of the soft, friable nature of the dried press cake the possibility of eliminating grinding was suggested. The question of bag-packing "Impedes* instead of using ply wood drums had previously been considered* A number of selected customers were supplied with the unground material in DUP050149727 w ^ 50 pound bag and asked for eMBts, As the replies vers favorable subsequent production was packed in bags and shipped la lump form* Anise the course of this work it was found that me lum-p g,a ve a; Xle;s-s, b-~alskay passage man the gronaft'material raettseumltpintag|toisusemaarpibprbooxnimmatiexe2rQt$o^--mTi*x30#in8 s*u. bJsMtawnskdaagerdcwmos*at.t.eriAasl end as a temporary bag-filling machine was unsuccessful* The nixing action seemed to increase the bulk of the material thus increasiag^packaga cost. Mixing is sow W sifting in substandard material fey hand daring the bag-paoking operation. 7. A single batch made is the large blue wait ssatrrixkxee vaast * Wat 180. tol"l -v-e--r-y- low" f-e---r-r--i-c i`r.o..n.....c..oanteteantt ((5$**fl$)) eevveens'tmhoouwg#h dried "aat ldW . It is postulated mat either or berth' of the following variations are responsible for the improved analytical result* "fee very slow paddle agitation (8 RPM) may slow up the relt^se of the SB* excess into the atmosphere thus inhibiting the information o? ferric salts. Ivan more likely is the possibility that it promotes the formation of larger aggregates thus decreasing the surface and slowing up oxidation in the dryer* b# The absence of a vent to the atmosphere increases the pressure of KB3 over the slurry thus cutting down the loss of Hh. This is an tan safe condition because of the considerable volume of ammonia released inside the operating building and production in Vat 180 will have to be stopped until a vent is supplied. / Recently another batch was made using these conditions under plant supervision and a low ferric iron content (6.96%) was again obtained. The plant is now awaiting definite assurances as to the production rate on "Impedes* in order to Justify the construction of a vent on Vat ISO. It is suggested that a decision regarding this be made as soon as possible so that the use of Vat 180 in "Impedes8 production may act as a deterrent to the manufacture of high ferric iron substandard material. A few of the process refinements developed during the course of the early work were embodied In a new formula, K-1904 (based on production in Vat 281) which differed from the laboratory procedure, K-1781, as follows* 1. The batch size is increased fro 10 mols to 12,75 aols. 2. Small variations in volumes are made based on plant equipment capacities. 3. The caustic soda amount is decreased approximately 4$. DUP050149728 7 4* The drying schedule Is charged from 44-48 hoars at 140-160F to 24-28 hows at 180%. A Still more reseat formula, K-2067, covers the productiQn in the yellow unit# The principle differences between K-2067 and K-1904 are* : 1 The heating, of the alkali solution before addict to the strike v, 2. Grinding is dispensed with and the material is packed oat in 58 pound paper bags instead of in plywood drums# Yields have been satisfactory# Results on 60 plant batches show an average figure of 99#6 of the estimate whleh is the equivalent of 98#6$ of theoretical# Paring the course of the development work on wIapedexB some thought had been given to the possibility of lowering Ingred ient costs# The greatest possibility for saving appeared to involve either a cheaper source of supply of secondary ammonium phosphate or the use of cheaper ingredients as a substitute for this material. Mean-while, there bad been some discussion with Grassell! as to the possibility of obtaining a cheap ammonium phosphate liquor from them which would give satisfactory results and still show an appreciable savings. Some material was supplied which was found to be satisfactory (as far as could be ascertained with incomplete tests) on a laboratory scale but nothing more was done because of the necessity of setting up semi-plant scale equipment at Grasselll in order to study their process further* This will not be done until some definite assurance can be given by Sewark as to the potential amount of ammonium phosphate that will be needed. In the early work some consideration had been given to the possibility of substituting other sources of ammonia and phosphate for the secondary ammonium phosphate originally selected. It was found at that time that phosphoric acid + ammonia, disodium phosphate and ammonia, or disodium phosphate and ammonium sulfate could be used* On this basis two Semi Works batches were made using a mixture of disodium phosphate and ammonium sulphate to supply material for evaluation. & batch (Lot 6455) made with an equivalent amount of these two ingradients to replace the diammonium phosphate and dried at 140f was well within the specification limits. 4 saving in ingredient cost of approximately 1/4 cent per pound of product is realised by this change# Fart of this batch was treated with additiohal ammonium phosphate before filtration* Mo advantage was obtained. DUP050149729 - 8Xa the second batch (Lot 6456) ft decreased amount of ammonium sulfate was used corresponding to a lowering of the ammonia excess from 10$ to 75J&. M overall saving In Ingredient cost of about %/Z east per pound of produot results from this variation* This batch gave satisfactory analytical figures* Part of this material dried at l&jr?* however* analysed slightly above the specification limit in ferric iron content. The UOF dried material, lots 6455 and 645$# have been placed cm exposure. The appearance of the panels is still satisfactory after about 3 months test but final results are not available as yet. When and if test data warrants it a revision of the "IapadexM formula to take advantage of this saving should be considered* DSN-43-15 DU P050149730