Treating processes copper chloride

The solvent method may also be performed either by continuous (in cascades) or by batch operation. Continuous techniques in particular have gained considerable technical importance. A phthalonitrile/copper chloride solution is typically treated at 120 to 140°C in a flow tube furnace and the temperature subsequently increased to 180 to 250°C. The entire process requires approximately 1.5 to 2 hours and affords the pigment in practically quantitative yield. The excellent purity of the product eliminates the need for additional purification with dilute acid or base prior to finishing, a procedure which plays a major role in the baking process. These... 

Sulfur compounds are most commonly removed or converted to a harmless form by chemical treatment with lye. Doctor solution, copper chloride, or similar treating agents (Speight, 1999). Hydrorefining processes (Speight, 1999) are also often used in place of chemical treatments. When used as a solvent, naphtha is selected for its low sulfur content and the usual treatment processes remove only sulfur compounds. Naphtha, with its small aromatic content, has a slight odor, but the aromatics increase the solvent power of the naphtha and there is no need to remove aromatics unless odor-free naphtha is specified. 

Other waste streams from the process result from water washing of the treated product and regeneration of the treating solution such as sodium plumbite (Na2Pb02) in doctor sweetening. These waste streams contain small amounts of oil and the treating material, such as sodium plumbite (or copper from copper chloride sweetening). 

Removal of the objectionable odors due to the presence of H2S and mercaptans is the objective of the fuel sweetening process. Several methods can be utilized to remove these undesirable compounds including caustic washing, copper chloride sweetening, sulfuric acid treating, Merox processing, and hydrotreating. These methods will be discussed below. 

Alkaline chlorination of wastewaters is one of the more widely used methods of treating cyanide wastes. In this process, cyanogen chloride (CNCl) is formed, which is hydrolyzed to the cyanate (CNO ) at alkaline pH. If free chlorine is present, CNO can be further oxidized. The use of sulfur dioxide in a high dissolved oxygen environment with a copper catalyst reportedly reduces total cyanide... 

Bronze disease necessitates immediate action to halt the process and remove the cause. For a long time, stabilization was sought by removal of the cuprous chloride by immersing the object in a solution of sodium sesquicarbonate. This process was, however, extremely time-consuming, frequentiy unsuccesshil, and often the cause of unpleasant discolorations of the patina. Objects affected by bronze disease are mostiy treated by immersion in, or surface appHcation of, 1 H-henzotriazole [95-14-7] C H N, a corrosion inhibitor for copper. A localized treatment is the excavation of cuprous chloride from the affected area until bare metal is obtained, followed by appHcation of moist, freshly precipitated silver oxide which serves to stabilize the chloride by formation of silver chloride. Subsequent storage in very dry conditions is generally recommended to prevent recurrence. 

Copper Sulfide—Cadmium Sulfide. This thin-film solar cell was used in early aerospace experiments dating back to 1955. The Cu S band gap is ca 1.2 eV. Various methods of fabricating thin-film solar cells from Cu S/CdS materials exist. The most common method is based on a simple process of serially overcoating a metal substrate, eg, copper (16). The substrate first is coated with zinc which serves as an ohmic contact between the copper and a 30-p.m thick, vapor-deposited layer of polycrystaUine CdS. A layer is then formed on the CdS base by dipping the unit into hot cuprous chloride, followed by heat-treating it in air. A heterojunction then exists between the CdS and Cu S layers. 

The second process to finish phthalocyanine, which is more important for P-copper phthalocyanine, involves grinding the dry or aqueous form in a ball mill or a kneader (64). Agents such as sodium chloride, which have to be removed by boiling with water after the grinding, are used. Solvents like aromatic hydrocarbons, xylene, nitrobenzene or chlorobenzene, alcohols, ketones, or esters can be used (1). In the absence of a solvent, the cmde P-phthalocyanine is converted to the a-form (57,65) and has to be treated with a solvent to regain the P-modification. The aggregate stmcture also has an impact on the dispersion behavior of a- and P-copper phthalocyanine pigments (66). 

The cymidiu sulphouic acid is then diazotised in the usual manner by treating with sodium nitrite in acid solution and the diazo body reduced with alkaline tin chloride solution, or with formic acid and powdered copper, or with other relatively gentle reducing agents. The 3 or 5 cymidin sulphonic acid gives by the above process one and the same cymene sulphonic acid, viz., l-methyl-3-sulphonic-4-isopropyl benzene. 

The solvent process involves treating phthalonitrile with any one of a number of copper salts in the presence of a solvent at 120 to 220°C [10]. Copper(I)chloride is most important. The list of suitable solvents is headed by those with a boiling point above 180°C, such as trichlorobenzene, nitrobenzene, naphthalene, and kerosene. A metallic catalyst such as molybdenum oxide or ammonium molybdate may be added to enhance the yield, to shorten the reaction time, and to reduce the necessary temperature. Other suitable catalysts are carbonyl compounds of molybdenum, titanium, or iron. The process may be accelerated by adding ammonia, urea, or tertiary organic bases such as pyridine or quinoline. As a result of improved temperature maintenance and better reaction control, the solvent method affords yields of 95% and more, even on a commercial scale. There is a certain disadvantage to the fact that the solvent reaction requires considerably more time than dry methods. 

Although silver is not treated by solvent extraction in any of the flow sheets, silver is recovered from aqueous solution in several other situations. For these processes, Cytec developed reagents with donor sulfur atoms to extract this soft element. For example, tri-isobutylphosphine sulfide (CYANEX 47IX) extracts silver from chloride, nitrate, or sulfate media selectively from copper, lead, and zinc [32]. The silver is recovered from the loaded organic phase by stripping with sodium thiosulfate, and the metal recovered by cementation or electrolysis. Silver can also be extracted from chloride solution by a dithiophosphinic acid (CYANEX 301) [33]. 

Cadmium is obtained as a byproduct in zinc recovery processes. The metal volatdizes during roasting of zinc concentrates and collected as dust or fume in bag houses or electrostatic precipitators. The dusts are mixed with coal (or coke) and zinc chloride and calcined. The cadmium chloride formed volatihzes upon calcination and thus separates out from zinc. The chloride then is treated with sulfuric acid in the presence of an oxidizing agent. This converts lead, present as impurity in cadmium ore, to lead sulfate which precipitates out. Cadmium is finally separated from copper by the addition of zinc dust and... 

The ARS Technologies, Inc., Ferox process is an in situ remediation technology for the treatment of chlorinated hydrocarbons, leachable heavy metals, and other contaminants. The process involves the subsurface injection and dispersion of reactive zero-valence iron powder into the saturated or unsaturated zones of a contaminated area. ARS Technologies claims that Ferox is applicable for treating the following chemicals trichloroethene (TCE), 1,1,1-trichloroethane (TCA), carbon tetrachloride, 1,1,2,2-tetrachloroethane, lindane, aromatic azo compounds, 1,2,3-trichloropropane, tetrachloroethene (PCE), nitro aromatic compounds, 1,2-dichloroethene (DCE), vinyl chloride, 4-chlorophenol, hexachloroethane, tribromomethane, ethylene dibromide (EDB), polychlorinated biphenyls (PCBs), Freon-113, unexploded ordinances (UXO), and soluble metals (copper, nickel, lead, cadmium, arsenic, and chromium). 

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