Document rBKod9KnppM8xGJV9MJ0kN7Yq

ANZ 0004183 AMERICAN SMELTING AND REFINING COMPANY Department of Environmental Sciences Salt Lake City, Utah Plant: CORPUS CHRISTI Field Work: Thomas J. Smith Survey Date: Report Date: April 21-23, 1971 August 25, 1971 Industrial Hygiene Survey 1. Operating Conditions: All operations were normal. Construction in the zinc reverberatory furnace area in the Sulfide Plant made noise evaluations difficult. 2. Sampling: One-hour sequential samples of airborne dust and fume were collected in several work areas by means of A.I.S.I. tape samplers. These samples were analyzed for lead and cad mium by atomic absorption spectrophotometry. Acid mist was sampled in the cell houses by means of membrane filters. However these samples were lost because of a problem with storage containers. Selected operations were sampled for fumes with personal monitor devices. Sulfur dioxide samples were collected in acidified hydrogen peroxide using two midget impingers in series following a membrane prefilter. Total sulfate collected was measured with a modified barium chloranilate technique. Noise levels were measured with a B and K Sound Level Meter, set on the A weighting network, and using the slow response setting. The meter was calibrated with a standard sound source before each set of measurements. Sampling Results: A. Airborne Dust - the average levels of airborne lead and cadmium in the Roaster Building and near the oxide crusher are shown below: Concentration (mg/m3) Location Pb / >0.2 mg/m3~ Cd / >0.1 mg/m- Roaster Bldg. .069 7 .014 0 Oxide Crusher .012 0 .025 0 ANZ 0004184 2- - Personal monitor are shown below: Operation samples taken in the Cadmium Sampling Time Department Cadmium Conc'n. (mg/m3) 1. Casting bars 35 min. . 021 2. Charging kettle p2 min. . 015 B. Sulfur dioxide concentrations on the third floor of the Roaster Building are given below: Location Sampling Time S02 Conc'n. (ppm) 1. On guard of #2 dry feed belt 2. Between roasters 3. Outside foreman's office 10 min. 12 min. 10 min. 7.9 2.9 2.0 Noise Levels: Location - Operation 1. Acid Plant Near blower Operator's area 2. Roaster Building 4 ft. from ball mill Center of ground floor Center ground floor with rapper on Near flush roaster, 2nd floor 3. Zinc Dust Furnace South platform area 4. Cell house - sulfide side Stripper operation Steam cleaning lance Buffing copper head bars 5. Cell house - oxide side Stripping floor dB( A) 87-88 76-78 89-90 79-81 92-93 89-90 89-90 88-90 105 99 88-90 Permissible Exposure -- 5 -- 1 2-1/2 ANZ 0004185 C. Noise Levels (cont.): Location - Operation dB( A) Permissible^ Exposure 6. Power House Ground floor (general) Top floor (general) Control room 38-90 92-94 35 4-1/2 7. Oxide Leach Building General 80-90 (average-86) 8. Oxide Ball Mills Between #1 and #2 Mills Leadman's office 89-92 71 7 9. Zinc Die Casting Area Stacking bars Work area by ladle of casting machine 95 90-96 4 * Permissible exposure allowed per 8-hour shift under the Occupational Safety and Health Act of 1970. Comments: Aside from the Roaster Building the overall conditions in the plant were excellent. Housekeeping was very good. The Roaster Building has some dust and sulfur dioxide problems. The roasters are inadequately sealed which allows dust and sulfur dioxide to permeate the upper floors of the building (See Photo). Although there was visible airborne dust, the sampling results did not indicate any hazardous concentrations of lead or cadmium. Sulfur dioxide was generally not present in excessive concentrations. However, there were localized areas near leaks in the roasters which had very noticeable sulfur dioxide. A new roaster to take the place of the existing roasters is presently under construction. This should alleviate the major source of industrial hygiene problems in the plant. Airborne cadmium levels were acceptably low in the Cadmium Department. The kettle for melting cadmium was well hooded and the molten metal surface was covered with molten caustic flux to prevent fuming. Personnel in this area made good use of protective equipment. There have been no recent reports of excessive cadmium excretion by men in this department. AN2 0004186 -4- Conditions in the cell houses were generally good but during calm weather conditions there were localized areas with enough acid mist in the air to cause transient eye and nasal irritation (See Photo). Based on the threshold for this type of irritation (N.I.Sax, Dangerous Properties of Industrial Materials). the airborne concentration of sulfuric acid mist was approximately 0.5 to 1.0 mg/m3. These levels approach the Occupational Safety and Health Act standard of 1.0 mg/m3 sulfuric acid mist averaged over an 8-hour shift. The zinc reverberatory furnace in the Sulfide Plant was releasing considerable amounts of fume into the charge floor. This was attributed to the furnace being too full of metal. Since a great deal of fume escaped from the building through the roof ventilator, there is a definite potential for an air pollution citation for an opacity violation. Closer supervi sion of furnace operations may be required. There were only a few areas with noise levels exceeding 90 dB(A). Considering the normal distribution of work activities, it is doubtful that any of the men exceeded the permissible exposures. Recommendations: A. The roasters should be kept as tightly sealed as practi cable to control local concentrations of dust and sulfur dioxide. B. During calm weather as much ventilation as possible should be provided to the work areas in the cell houses, in order to prevent any accumulation of acid mist. C. Noise exposures should be checked by observing work activi ties in noisy areas to be certain that the limits are not being exceeded. TJS/bbc Enel. cc: CBWhite HLMontague KDLoughrldge DHSoutar AJGillespie,Jr. EHHaug Dr.SSPinto RCBeckstead KWNelson Thomas J. Smith, Ph.D. Environmental Scientist ANZ 0004187 ANZ 0004188 A irb o rn e Lead (mg/m3 ) A irb o rn e Cadmium (m g / ANZ 0004189 A irb o rn e Lead (m^/rn3 ) A irb o rn e Cadmium (m g / Roaster Building - third floor Noticeable dust and sulfur dioxide Dresent I Cell House - showing the acid mist present during calm weather ANZ 0004190