CYANIDE in WATER and SOIL: Chemistry, Risk, and Management - Chapter 4 pdf

4 Manufacture and the Use of Cyanide George M. Wong-Chong, David V. Nakles, and Richard G. Luthy CONTENTS 4.1 Production of Cyanide Compounds 42 4.1.1 Hydrogen Cyanide 42 4.1.2 Production of Sodium Cyanide 42 4.1.2.1 Global and U.S. Production 42 4.1.2.2 Production Methods 44 4.1.3 Production of Ferrocyanides 48 4.1.4 Production of Acrylonitrile 49 4.1.4.1 Global and U.S. Production 49 4.1.4.2 Production Methods 50 4.2 Incidental Industrial Production of Cyanide 51 4.2.1 Coking and Gasification of Coal 52 4.2.2 Blast Furnace Operations 52 4.2.3 Aluminum Production 52 4.2.4 Municipal Waste and Sludge Incineration 53 4.3 Summary and Conclusions 53 References 54 Cyanide, a natural compound found in plants and animals, is believed to be a key component in the in the manufacture of a number of products including synthetic fibers and plastic, gold, agricul- tural herbicides, fumigants and insecticides, dyes and pigments, animal feed supplements, chelating breakdown of the overall industrial use of hydrogen cyanide, including as a feedstock chemical for that use cyanide compounds in the manufacturing process, along with the cyanide compounds employed. The cyanide industry traces its history to about 1710 with the discovery of Prussian Blue (or ferric ferrocyanide), an iron cyanide compound, which at that time was used almost exclusively in dye- ing [3,4]. However, it was not until about 1885 that substantial commercialization of cyanide, specifically potassium cyanide, occurred with the development of the McArthur-Forest process, known today as the cyanidation process, for the extraction of gold from low-grade ores [3]. This discovery represents a major sustaining factor in today’s cyanide commerce, with about 20%, or an estimated 0.6 million tons, of the worldwide production of cyanide used in mining [5,6]. This chapter discusses the manufacture of cyanide compounds, especially hydrogen cyanide, sodium cyanide, ferrocyanide, and acrylonitrile, as well as the uses of these compounds and their 41 © 2006 by Taylor & Francis Group, LLC agents for water treatment, and specialty chemicals and pharmaceuticals [1,2]. Table 4.1 presents a production of other cyanide compounds, as of 1991. Table 4.2 presents a list of some industries origin of life (see Chapter 1) and plays a pivotal role in today’s commerce. It is a basic component 42 Cyanide in Water and Soil TABLE 4.1 Use of Hydrogen Cyanide in Manufacturing in the United States (1991 Estimate) Product HCN used (%) Adiponitrile for nylon 41 Acetone cyanohydrin for plastics 28 Sodium cyanide 13 Cyanuric chloride for pesticides and agricultural products 9 Chelating agents (e.g., EDTA) 4 Methionine, animal feed 2 Misc.: specialty chemicals and pharmaceuticals 3 Source: Data from Pesce, L.D., Kirk–Othmer Encyclopedia of Chemical Technology, Vol. 7, John Wiley & Sons, New York, 1993. production rates. The chapteralsodiscusses thoseindustrieswhere cyanide productionisan incidental occurrence, such as in coking and gasification of coal, metal ore reduction in blast furnaces, the reduction of alumina, and municipal waste and sludge incineration. 4.1 PRODUCTION OF CYANIDE COMPOUNDS 4.1.1 H YDROGEN CYANIDE In 2001, the worldwide production of hydrogen cyanide was approximately 2.6 million tons [6]. The U.S. production in the period 1983 through 2001 was 0.33 to 0.75 million tons per year, as shown in There are four commercial processes for the production of hydrogen cyanide. Two of these are synthesis processes involving the reaction of ammonia, methane (natural gas), and air over a platinum catalyst: (1) the Andrussow process and (2) the Blausaure–Methan–Ammoniak (BMA) process. A third process, the Shawinigan process, uses a carbon fluid bed in an electrical fluohmic furnace to react ammonia and propane. The fourth process is the acrylonitrile production process where hydrogen cyanide is produced as a by-product and which accounts for about 30% of worldwide cyanide. The Andrussow process, which is by far the dominant manufacturing process, produces hydrogen cyanide via the following reaction [2]: CH 4 +NH 3 +1.5O 2 → HCN +3H 2 O (4.1) recovery/recycle of ammonia and waste heat-design features that improve the efficiency and economy of the process. Details of the process are available in the Kirk–Othmer Encyclopedia of Chemical Technology [2]. 4.1.2 PRODUCTION OF SODIUM CYANIDE 4.1.2.1 Global and U.S. Production The McArthur-Forest patent for gold extraction from ore with cyanide was issued in 1887 and the cyanidation process was first used in the Crown Mine in New Zealand and then elsewhere in the © 2006 by Taylor & Francis Group, LLC Table 4.3. supply [2]. Table 4.4 presents summary information about the synthesis processes for hydrogen Figure 4.1 presents a schematic flow diagram of the Andrussow process. This diagram shows the Manufacture and the Use of Cyanide 43 TABLE 4.2 Use of Cyanide Compounds in Manufacturing Industries Primary cyanide compounds Industry used in the process References Adhesives Ammonium thiocyanate [14] Cement stabilizer Calcium cyanide [15] Electroplating Potassium- or sodium-cyanide (degreasing) Propionitrile (solvent, dielectric fluid) Nickel cyanide Silver cyanide Barium cyanide Zinc cyanide Copper cyanide Hydrogen cyanide Cyanogen chloride (metal cleaner) Mercuric potassium cyanide (mirror manufacturing) [14–18] Fire retardant Potassium ferrocyanide [19,20] Herbicides Ammonium thiocyanate [14,21] Fumigant, poison gas, pesticides, insecticides, parasiticide Cyanogen Cyanogen chloride Cyanogen bromide Zinc cyanide Copper cyanide Calcium cyanide Hydrogen cyanide Ammonium thiocyanate (pesticides) [14,15] Mining Sodium cyanide Malononitrile Cyanogen bromide Barium cyanide Calcium cyanide Ferrocyanide (used as a flotation agent for copper and lead/zinc separation) [14–17] Petroleum Malononitrile (lubricating oil additive) Propionitrile (solvent) [15] Photography Ferricyanide bleach Mercuric cyanide Hydrogen cyanide [17,22–24] Pharmaceuticals (includes antibiotics, steroids, prescription and nonprescription drugs) Ferricyanide Ferrocyanide Propionitrile Ammonium thiocyanate (ingredient in antibiotic preparations) [14,15,22,24] (continued) © 2006 by Taylor & Francis Group, LLC 44 Cyanide in Water and Soil TABLE 4.2 Continued Primary cyanide compounds Industry used in the process References Pigments, paints, dyes, ink, personal care products Ferricyanide Ferrocyanide Ferric ferrocyanide (Prussian blue, Fe 4 (Fe(CN) 6 ) 3 ) Malononitrile Mercuric cyanide (germicidal soap) Copper cyanide (marine paint) [15,25–27] Road salt Sodium ferrocyanide Ferric ferrocyanide (Prussian blue, Fe 4 (Fe(CN) 6 ) 3 ) Potassium ferrocyanide [17,28–30] Rocket and missile propellant Cyanogen Ammonium thiocyanate [14,15] Synthetic fiber, acrylic fiber, nylon, synthetic rubber Malononitrile Adiponitrile (intermediate in the manufacture of nylon) Cyanogen bromide Cyanogen chloride Hydrogen cyanide (production of nylon and other synthetic fibers and resins) Ammonium thiocyanate (improve the strength of silks) [14–16,31] Wine Potassium ferrocyanide [32] Source: Data from MPI, Final Technical Memorandum: Summary of cyanide investiation at SRWTP and preliminary conclusions and recommendations, report by Malcolm Pirnie, Inc., Emeryville, CAtotheSacramentoRegional County Sanitation District, Sacramento Regional Wastewater Treatment Plant, Regulatory Compliance Group, Sacramento, CA, 2004. 1890s. This process started the new field of hydrometallurgy. With the advent of this process, world production of potassium cyanide rose from 5,900 tons per year in 1899 to 21,000 tons per year in 1915 [2,3]. Sodium cyanide eventually replaced the potassium salt for economic reasons, and has been the cyanide salt used in hydrometallurgical gold extraction solutions for many years. Production and use of sodium cyanide has been growing. Global annual usage of sodium cyanide in 1989 was about 340,000 tons. In the early 1990s, the total world production of sodium cyanide was estimated to be in excess of 450,000 tons. In 2001, the global production rate was about 600,000 tons per year [2,6]. 4.1.2.2 Production Methods In 1906, Robine and Lenglen [3] cited 79 processes for the production of potassium cyanide: 10 processes involving extraction from ferrocyanide; 13 processes involving extraction from thiocyanate; 28 processes involving synthesis from atmospheric nitrogen; 24 processes involving synthesis from ammonia; and four other processes. In 1891 through 1899, the Beilby process — involving synthesis from ammonia, sodium and potassium carbonate, and powdered charcoal — accounted for about 50% of the total European production of alkali cyanide [2]. In 1900, the Castner © 2006 by Taylor & Francis Group, LLC Manufacture and the Use of Cyanide 45 TABLE 4.3 Production of Hydrogen Cyanide in the United States, 1983–2001 Production a , Year 10 3 tons/yr 2001 750 2000 765 1999 745 1998 725 1997 710 1996 695 1995 675 1994 645 1993 600 1992 570 1991 565 1990 585 1989 565 1988 500 1987 470 1986 430 1985 365 1984 365 1983 330 a Production estimates for 1983–1988; Source: Data from Pesce, L.D., Kirk–Othmer Encyclopedia of Chemical Technology, Vol.7, John Wiley & Sons, New York, 1993. Production estimates for 1989–2001; Source: Data from Myers, E., American Chemistry Council, Washington, DC, personal commu- nication, 2002. TABLE 4.4 Synthesis Processes for Hydrogen Cyanide Process Catalysts Temperature, ◦ C Feed Andrussow Platinum/rubidium 1100 NH 3 , air, and CH 4 Blausaure–Methan–Ammoniak Platinum 1100 NH 3 and CH 4 Shawinigan Carbon fluid bed in a fluohmic furnace 1350–1650 NH 3 and C 3 H 8 Acrylonitrile process By-product 400–510 NH 3 , air, and C 3 H 6 Source: Data from Pesce, L.D., Kirk-Othmer Encyclopedia of Chemical Technology, Vol. 7, John Wiley & Sons, New York, 1993. © 2006 by Taylor & Francis Group, LLC 46 Cyanide in Water and Soil NH 3 Fractionator NH 3 /Water NH 3 Absorber Steam Waste- water NH 3 Stripper Diammonium Phosphate Solution Monoammonium Phosphate Solution Waste-Heat Boiler Reactor NH 3 Feed Air Feed Natural Gas Feed NH 3 Recycle HCN Fractionator HCN Absorber Coolers HCN Stripper Acid HCN/Water Steam SO 2 Waste Water HCN/Water HCN with SO Inhibitor 2 Waste Gases to Boiler or Flare Off-Gas Minus N H 3 FIGURE 4.1 Schematic flow diagram of the Andrussow hydrogen cyanide production process. (Source: Pesce, L.D., Kirk–Othmer Encyclopedia of Chemical Technology, Vol. 7, John Wiley & Sons, New York, 1993. Reprinted with Permission of John Wiley & Sons, Inc.) process replaced the Beilby process and dominated production through 1960 for both potassium and sodium cyanide. For the production of sodium cyanide, the Castner process employs elemental sodium and a reaction with ammonia and carbon as follows: 2Na +2NH 3 +2C → 2NaCN +3H 2 (4.2) Low yields and elevated costs led to the obsolescence of the Castner process. This process was replaced by the neutralization or wet processes that react hydrogen cyanide from the Andrussow or BMA processes with a sodium hydroxide solution: HCN +NaOH → NaCN +H 2 O (4.3) Most modern, high tonnage production plants use essentially purified anhydrous liquid hydrogen cyanide to react with sodium hydroxide to produce a product consisting of 99% sodium cyanide. The manufacturing process includes the evaporation of water and crystallization of the sodium cyanide. Control of the process is critical to maximize the average crystal size; to avoid hydrogen © 2006 by Taylor & Francis Group, LLC Manufacture and the Use of Cyanide 47 Vacuum system Condenser Crystallizer System Filter Air Heater Dehumidifier Scrubber Waste Mixing Conveyor Briquetter Screens Separator Dust Scrubber Cyclone Product to packaging and storage 50% Caustic Hydrogen cyanide Steam FIGURE 4.2 Production process flow diagram for sodium cyanide. (Source: Pesce, L.D., Kirk–Othmer Encyclopedia of Chemical Technology, Vol. 7, John Wiley & Sons, New York, 1993. Reprinted with permission of John Wiley & Sons, Inc.) cyanide polymer formation, which produces an off-white product; and to minimize sodium formate formation, which reduces product purity. Figure 4.2 presents a process flow diagram for a typical sodium cyanide production plant. An occasionally used, alternative process is the direct absorption of crude hydrogen cyanide gas from the manufacturing operation into a sodium hydroxide solution. However, the purity of the sodium cyanide product is lower, that is, approximately 96 to 97% [2]. The primary impurities are sodium carbonate and sodium formate. The formation of larger crystals facilitates the dewatering in the filtration step. In many plants, the moist salt from the filter is passed through a mixing conveyor to destroy the lumps. Often, heated air (450 ◦ C) is passed through the cake on the filterand through the mixing conveyor. Drying is completed in a hot-air conveyor-dryer. This approach to drying avoids the overheating of the sodium cyanide crystals, thus minimizing the formation of sodium formate in the dried product. A slight excess of sodium hydroxide must be maintained at all stages of processing to maintain an elevated pH, which © 2006 by Taylor & Francis Group, LLC 48 Cyanide in Water and Soil prevents the formation of a black or brown hydrogen cyanide polymer. The product, as shipped, must also contain a slight excess of sodium hydroxide, to ensure that the product yields clear solutions following arrival at its destination. Inherently, the sodium cyanide forms a 50-µm diameter crystal, yielding a dusty solid of low bulk density that must be compacted or fused into larger particles for safer handling. Due to the expense associated with melting the product for casting it in molds, most processes employ mechanical compacting devices that produce either briquettes or granular products. The compaction process occurs using heat and pressure. Most sodium cyanide is sold in dry form to minimize transportation costs although appreciable tonnage is also sold as a 30% aqueous solution [2]. About 90% of today’s sodium cyanide is used in gold extraction [5,6]. Plants for the production of sodium cyanide, using these processes, are operating in the United States, Italy, Japan, the United Kingdom, Australia, Germany, and China. 4.1.3 PRODUCTION OF FERROCYANIDES Ferric ferrocyanide, also known as Prussian Blue (Fe 4 [Fe(CN) 6 ] 3 ), was the first cyanide compound put to commercial use. The compound was discovered by a Berlin color maker in 1704 [3]. This led to a long history of ferrocyanide chemistry, which has resulted in the use of these compounds in a wide variety of industrially significant applications. A treatise on the chemistry of ferrocyanides [7] describes some 22 applications, and these are listed in Table 4.5. In the late 1700s through the early 1900s, ferrocyanide salts were produced by (1) the synthetic fusion of nitrogenous organic residues (e.g., animal blood, hides, hornes, waste/scrap leather, etc.), potash, and iron, and (2) the direct extraction from illuminating-gas and from the by-product TABLE 4.5 Uses of Ferrocyanides and their Derivatives in Industry Analytical chemistry Anticaking agent Blueprints Case hardening and heat treatment of steel Chemical synthesis: catalysts, reaction intermediates, and reagents Chemotherapy Corrosion inhibitors Desulfurization of coke oven gas Detergents Dying of textiles Electrical equipment treatment: corrosion resistance; arc stabilization and lowering of grounding resistance Electroplating Minerals dressing, beneficiation, and mining Pesticides Petroleum refining: trace metals removal Photography Pigments and dyes Pickling of steel Rubber: peptizing agent, stabilization agent, and accelerator Separation and identification of organic bases Trace metals removal in fermentation Source: Data from ACC, The Chemistry of the Ferrocyanides, American Cyanamid Co., New York, NY, 1953. © 2006 by Taylor & Francis Group, LLC Manufacture and the Use of Cyanide 49 of illuminating-gas clean-up (e.g., spent iron oxide boxes for gas purification) [3]. It was estimated that about 1.8% of the nitrogen in coal reacted to form hydrogen cyanide during coal gasification. In the direct gas extraction processes, the illuminating gas was scrubbed with an alkaline iron salt solution. Robine and Lenglen [3] discussedin detail nineprocesses for the direct extraction of cyanide from illuminating gas, three processes for extraction from ammoniacal liquor, and 11 processes for recovering ferrocyanide from spent iron oxide. In the synthesis from nitrogenous organic matter, the process chemistry for making potassium ferrocyanide was thought to be: K 2 CO 3 +Nitrogenous Matter +Energy → KCN +··· (4.4) 6KCN +Fe 2+ → K 4 Fe(CN) 6 +2K + (4.5) In the first reaction, hydrogen cyanide is produced by the thermal breakdown of the organic matter in an oxygen controlled environment (Equation [4.4]). Subsequently, the hydrogen cyanide reacts with potassium to form potassium cyanide. The potassium cyanide, in turn, reacts with the iron to form potassium ferrocyanide as shown in Equation (4.5). Today, ferrocyanide production utilizes the crude sodium cyanide, produced as described in Section 4.1.2, and ferrous sulfate to form sodium ferrocyanide: 6NaCN +FeSO 4 +Heat → Na 4 Fe(CN) 6 +Na 2 SO 4 (4.6) The sodium ferrocyanide is recovered by crystallization as the decahydrate salt. The potassium salt is produced by reacting sodium ferrocyanide with calcium hydroxide and potassium chloride and carbonate according to the following reactions: Na 4 Fe(CN) 6 +2Ca(OH) 2 → Ca 2 Fe(CN) 6(s) +4Na(OH) (4.7) Ca 2 Fe(CN) 6 +2K 2 CO 3 → K 4 Fe(CN) 6 +CaCO 3(s) (4.8) In earlier times, ca. 1900, Prussian Blue was produced in a two stage process. The first stage reacted potassium ferrocyanide and ferrous sulfate to form a grayish-white precipitate of potassium ferric–ferrocyanide. In the second stage, the potassium ferric–ferrocyanide is oxidized to the tetrairon(III) tris(hexakiscyanoferrate), Fe 4 [Fe(CN) 6 ] 3 [3]. Today, the production of Prussian Blue is more direct, where ferrocyanide is reacted with excess iron(III) to produce the intense blue precipitate [2]. 4.1.4 PRODUCTION OF ACRYLONITRILE Acrylonitrile [C 3 H 3 N], also called vinyl cyanide, is among the top 50 chemicals produced in the United States as a result of the tremendous growth in its use as a starting material for a wide range of chemical and polymerproducts. Acrylicfibers remainthelargestuse ofacrylonitrile. Othersignificant uses are resins and nitrile elastomers and as an intermediate in the production of adiponitrile and acrylamide. 4.1.4.1 Global and U.S. Production Worldwide production of acrylonitrile was approximately 3.2 million tons in 1988 [8]. As shown States. In the United States, BP Chemicals dominated production, supplying more than one-third of domestic production. Nearly one-half of the United States production was exported in 1988, with most going to Japan and the Far East [8]. This export market grew steadily from the mid-1970s © 2006 by Taylor & Francis Group, LLC in Table 4.6, more than one-half of that production was located in Western Europe and the United 50 Cyanide in Water and Soil TABLE 4.6 Worldwide Acrylonitrile Production, 1988 Region Production, 10 3 tons Western Europe 1200 United States 1170 Japan 600 Far East 200 Mexico 60 Total 3230 Source: From Brazdil, F., Kirk-Othmer Encylopedia of Chemical Technology, Vol. 1, John Wiley & Sons, New York, 1993. TABLE 4.7 Worldwide Acrylonitrile Demand, 10 3 Tons per Year Region 1976 1980 1985 1988 Western Europe 880 880 1140 1200 Japan 570 510 635 680 United States 590 660 640 660 Far East 200 270 385 560 Mexico/South America 81 130 200 250 Total 2321 2450 3000 3350 Source: Data from Brazdil, F., Kirk–Othmer Encyclopedia of Chemical Technology, Vol. 1, John Wiley & Sons, New York, 1993. to 1988. During this period, it increased from 10% in the mid-1970s to 53% and 43% in 1987 and 1988, respectively. The large exports to the Far East were the result of higher raw material costs (i.e., propylene costs) relative to the United States. A more detailed breakdown of the world demand for acrylonitrile for the period between 1976 and 1988 is provided in Table 4.7. Growth in demand during this period averaged about 3.6% per year between 1984 and 1988. Projections beyond 1988 were 3% per year through 1993. 4.1.4.2 Production Methods Prior to 1960, processes based on either ethylene oxide and hydrogen cyanide or acetylene and hydrogen cyanide were used to produce acrylonitrile. Growth in the demand for acrylic fibers around 1950 spurred improvements in process technology and resulted in the discovery of a heterogeneous vapor-phase catalytic process. This process, which produced acrylonitrile using selective oxidation of propylene and ammonia, is commonly referred to as the propylene ammoxidation process. This process was introduced in 1960 and eventually displaced all other acrlyonitrile manufacturing pro- cesses. As of 1988, over 90% of the approximately 3.2 million metric tons of acrylonitrile produced worldwide each year was manufactured using the propylene ammoxidation process [8]. © 2006 by Taylor & Francis Group, LLC [...]... Group, LLC Cyanide in Water and Soil 54 • Various cyanide compounds are produced incidentally during the manufacture of coke, steel, and aluminum, and during the incineration of municipal waste and wastewater sludges REFERENCES 1 Homan, E.R., Reactions processes and materials with potential for cyanide exposure, in Clinical and Experimental Toxicology of Cyanides, Ballantyne, B and Marrs, T.C., Eds.,... temperature and availability of nitrogen and carbon, provide the opportunity for hydrogen cyanide formation This cyanide leaves the incinerator in the exhaust gases and is transferred to the off-gas scrubbing water At the Cranston, Rhode Island POTW, an average of 2.08 g cyanide per kilogram of dry sludge incinerated is removed in the scrubber water [13] 4. 3 SUMMARY AND CONCLUSIONS • Hydrogen cyanide and other... removed by bag-houses and dry scrubbing and the remaining 30% by wet scrubbing The hydrogen cyanide that is present in the gas is removed during the wet scrubbing process and reports to the blast furnace gas scrubber water 4. 2.3 ALUMINUM PRODUCTION Aluminum is manufactured via the electrometallurgical reduction of alumina (Al2 O3 (s)) in the Hall– Heroult process [2,11] The alumina is placed in a molten... at the end of a pot liner processing life, the cyanide concentration can be as high as 0.9% by weight [11] Cyanide levels vary within a pot, with highest concentrations observed in the potlining at the side walls Spent potlining containing cyanide and other contaminants is removed for treatment and disposal Until the early 1970s, spent potlining was managed as an inert residue and was often used as... assembly industry, EPA-310/R-9 5-0 09, U.S Environmental Protection Agency, Washington, D.C., 1995 32 USEPA, Consumer fact sheet on cyanide, U.S Environmental Protection Agency, Office of Ground Water and Drinking Water, http://www.epa.gov/ogwdw/dwh/c-ioc /cyanide. html Accessed: February 25, 2005 33 MPI, Final Technical Memorandum: Summary of cyanide investigation at SRWTP and preliminary conclusions and recommendations,... INCINERATION In areas where land-disposal of municipal wastewater treatment sludge is not practical, sludge incineration is an accepted disposal alternative In some instances, the economics are improved by combined incineration of municipal refuse and sludge coupled with co-generation of electricity In the northeastern states of Massachusetts and Rhode Island, municipal wastewater sludge incineration... sample stability of cyanide in industrial effluents, J Water Pollut Control Fed., 52, 11, 1980 25 USEPA, Seminar publication — National conference on urban runoff management: Enhancing urban watershed at the local, county and state levels, EPA-625/R-9 5-0 03, U.S Environmental Protection Agency, Washington, D.C., 1995 26 USEPA, Profile of the wood furniture and fixtures industry, EPA-310/R-9 5-0 03, U.S Environmental... of nitrogen and carbon The quantity of cyanide produced in the coking of coal has been reported to be about 1.5 to 2.0% of the nitrogen content of the coal [3] A portion of the cyanide remains in the coke oven gas while the remainder leaves the coking system in the waste ammonia liquor wastewater [3] In the early days of the cyanide industry, ca 1900, cyanide was recovered from illuminating-gas production,... operations follow More details and discussions of these operations are presented in Chapter 26 © 2006 by Taylor & Francis Group, LLC 52 Cyanide in Water and Soil 4. 2.1 COKING AND GASIFICATION OF COAL The coking operation involves distillation of coal by indirectly heating the coal in the absence of air to temperatures in the range of 900 to 1100◦ C to vaporize all volatile constituents in the coal [9] These... of Medicine, http://toxnet.nlm.nih.gov, accessed: February 18, 2005 16 Boucabeille, C., Bories, A., Olliver, P., and Michel, G., Microbial degradation of metal complexed cyanides and thiocyanate from mining wastewaters, Environ Pollut., 84, 59, 19 94 17 Kjeldsen, P., Behaviour of cyanides in soil and groundwater: a review, Water, Air, Soil Pollut., 115, 279, 1999 18 Patterson, J.W., Cyanide, in Industrial . Sodium Cyanide 42 4. 1.2.1 Global and U.S. Production 42 4. 1.2.2 Production Methods 44 4. 1.3 Production of Ferrocyanides 48 4. 1 .4 Production of Acrylonitrile 49 4. 1 .4. 1 Global and U.S. Production 49 4. 1 .4. 2. LLC discussed in more detail in Chapter 27. 54 Cyanide in Water and Soil • Various cyanide compounds are produced incidentally during the manufacture of coke, steel, and aluminum, and during the incineration. thiocyanate (ingredient in antibiotic preparations) [ 14, 15,22, 24] (continued) © 2006 by Taylor & Francis Group, LLC 44 Cyanide in Water and Soil TABLE 4. 2 Continued Primary cyanide compounds Industry