Recycling nickel from

The obvious destination for nickel waste is in the manufacture of stainless steel, which consumes 65% of new refined nickel production. Stainless steel is produced in a series of roasting and smelting operations. These can be hospitable to the various forms of nickel chemical waste. In 1993, 3 x 10 t of nickel from nickel-containing wastes were processed into 30 x 10 t of stainless steel remelt alloy (205,206) (see Recycling, nonferrous metals). This quantity is expected to increase dramatically as development of the technology of waste recycle coUection improves. 

Generally water is used, in a nickel sulfate plant for process reaction, cooling of reactor, crystallization, plant washdown of spills, pump leaks and general cleanup. The water used in the process reaction is for preliminary preparation of the spent plating solution. In other units, especially where impure nickel raw material is used, the wastewater is often recycled. Wastewaters from this plant contain contact and noncontact water, which predominantly contain nickel as a major impurity. 

The residue after the water wash is leached at an elevated temperature by sulfuric acid, part of which is the recycled raffinate from the vanadium extraction. The leaching yield of vanadium (mainly IV-valent) is about 55% and of nickel about 95%. A final (post) leach with sodium hydroxide dissolves the remaining vanadium (mainly V-valent). The resulting leach solution, containing practically all the vanadium ( 25gdm ) and nickel ( 12gdm ) is fed to the solvent extraction circuit. 

There is only one nickel mine in operation in the United States. The mine is located in Riddle, Oregon. Most of our new nickel is imported from Canada. Much of our domestic nickel comes from recycling nickel-containing alloys. 

Nickel Sulfamate. Vltramon, a Thomas and Betts subsidiary, installed a 1 gpm ARO system to recover rinses and recycle nickel bath used to plate electronic capacitors. Previously, Vitramon had used an ion exchange system to remove the nickel. Ion exchange regenerant was shipped to a reclaimer. Water was reused. Ion exchange cost of operation was 4,000 per month. The ARO system maintains the rinse at less than 40 ppm nickel. Savings from nickel recovery and avoided treatment cost will provide a payback of approximately 10 months. 

The combined recycling capacity world wide was about 25,000 metric tons of Ni/Cd batteries per year in 1993, but this was significantly underutilized because of inefficient collection systems and low prices for nickel and cadmium. Both pyrometallurgical and hydrometallurgical methods are used to recycle cadmium from a variety of waste materials in plants in North America, Europe, and Japan [24]. Cadmium is relatively easy to separate from other materials because of its low melting point and chemical activity. 

All reforming processes comprise a pretreatment section designed to remove feedstock compounds that are harmful to the catalyst sulfur, nitrogen and metals. This involves hydrodesulfurization. or hydrodeni nation if need be, which takes place in the presence of catalysts based on cobalt and molybdenum or nickel and molybdenum on alumina support, at a temperature of about 320 to 380°C, and a hydrogen partial pressure of around ft5 to 0.8.106 Pa, with LHSV of 5 to 12 h and hydrogen recycle ratios from 50 to 75 hy volume. 

In the USA, approximately 10% of nickel that is consumed per year undergoes recycling. Nickel-bearing materials, mostly from the steel industry, are melted, refined, and used to prepare alloys similar in composition to those that enter the recycling process. 

A. Recycling cobalt from batteries to custom smelters. Large Ni-Co custom smelters are usually equipped to recycle also cobalt (and nickel) from batteries. As an example, Xstrata Nickel... 

Recycling Cobalt From Nickel Refinery Sludges Residues... 

The stoichiometric and the catalytic reactions occur simultaneously, but the catalytic reaction predominates. The process is started with stoichiometric amounts, but afterward, carbon monoxide, acetylene, and excess alcohol give most of the acrylate ester by the catalytic reaction. The nickel chloride is recovered and recycled to the nickel carbonyl synthesis step. The main by-product is ethyl propionate, which is difficult to separate from ethyl acrylate. However, by proper control of the feeds and reaction conditions, it is possible to keep the ethyl propionate content below 1%. Even so, this is significantly higher than the propionate content of the esters from the propylene oxidation route. 

The reaction is initiated with nickel carbonyl. The feeds are adjusted to give the bulk of the carbonyl from carbon monoxide. The reaction takes place continuously in an agitated reactor with a Hquid recirculation loop. The reaction is mn at about atmospheric pressure and at about 40°C with an acetylene carbon monoxide mole ratio of 1.1 1 in the presence of 20% excess alcohol. The reactor effluent is washed with nickel chloride brine to remove excess alcohol and nickel salts and the brine—alcohol mixture is stripped to recover alcohol for recycle. The stripped brine is again used as extractant, but with a bleed stream returned to the nickel carbonyl conversion unit. The neutralized cmde monomer is purified by a series of continuous, low pressure distillations. 

Fresh reducing gas is generated by reforming natural gas with steam. The natural gas is heated in a recuperator, desulfurized to less than 1 ppm sulfur, mixed with superheated steam, further preheated to 620°C in another recuperator, then reformed in alloy tubes filled with nickel-based catalyst at a temperature of 830°C. The reformed gas is quenched to remove water vapor, mixed with clean recycled top gas from the shaft furnace, reheated to 925°C in an indirect fired heater, and injected into the shaft furnace. For high (above 92%) metallization a CO2 removal unit is added in the top gas recycle line in order to upgrade the quaUty of the recycled top gas and reducing gas. 

Nickel sulfate also is made by the reaction of black nickel oxide and hot dilute sulfuric acid, or of dilute sulfuric acid and nickel carbonate. The reaction of nickel oxide and sulfuric acid has been studied and a reaction induction temperature of 49°C deterrnined (39). High purity nickel sulfate is made from the reaction of nickel carbonyl, sulfur dioxide, and oxygen in the gas phase at 100°C (40). Another method for the continuous manufacture of nickel sulfate is the gas-phase reaction of nickel carbonyl and nitric acid, recovering the soHd product in sulfuric acid, and continuously removing the soHd nickel sulfate from the acid mixture (41). In this last method, nickel carbonyl and sulfuric acid are fed into a closed-loop reactor. Nickel sulfate and carbon monoxide are produced the CO is thus recycled to form nickel carbonyl. 

The solvent is 28 CC-olefins recycled from the fractionation section. Effluent from the reactors includes product a-olefins, unreacted ethylene, aluminum alkyls of the same carbon number distribution as the product olefins, and polymer. The effluent is flashed to remove ethylene, filtered to remove polyethylene, and treated to reduce the aluminum alkyls in the stream. In the original plant operation, these aluminum alkyls were not removed, resulting in the formation of paraffins (- 1.4%) when the reactor effluent was treated with caustic to kill the catalyst. In the new plant, however, it is likely that these aluminum alkyls are transalkylated with ethylene by adding a catalyst such as 60 ppm of a nickel compound, eg, nickel octanoate (6). The new plant contains a caustic wash section and the product olefins still contain some paraffins ( 0.5%). After treatment with caustic, cmde olefins are sent to a water wash to remove sodium and aluminum salts. 

The reactor outlet is flashed to remove ethylene which is then compressed and recycled a-olefins are separated from the solvent that contains the catalyst, treated to remove catalyst, and then distilled into commercial fractions. Most of the catalyst in the solvent is recycled but a portion is purged. The catalyst in the purge stream is recovered by reducing the oxidized nickel with boron hydride. 

The mixture can be separated by distillation. The primary phosphine is recycled for use ia the subsequent autoclave batch, the secondary phosphine is further derivatized to the corresponding phosphinic acid which is widely employed ia the iadustry for the separation of cobalt from nickel by solvent extraction. With even more hindered olefins, such as cyclohexene [110-83-8] the formation of tertiary phosphines is almost nondetectable. 

Fig. 1. Recycling of the nonferrous metals ( ) lead, ( ) nickel (stainless steel), (U) copper, (S) aluminum, and ( ) 2iac from secondary sources from 1989...

Cobalt. There is no U.S. mine production of cobalt. Refining of imported nickel—cobalt mattes has not occurred since the mid-1980s. About 1600 t of secondary cobalt was recycled from scrap by 13 faciUties in the United States representing - 22% of total U.S. consumption. The price of the metal was around 44/kg. Most is imported from Zaire and Zambia. Increasing quantities are coming from Russia. Historically, the price of cobalt has been quite volatile and dependent on the pohtical environment in those countries. Cobalt is used in superaHoys, 40% catalysts, 14% paint driers, 11% magnetic alloys, 10% and cemented carbides and other uses, 16%. 

Nickel. Around 56,000 t of nickel were recycled from scrap in 1994. This is just over one-third of the consumption of the metal. The only mining and smelter in the United States was idle in 1994, although INMETCO (EUwood City, Peimsylvania) was a primary consumer of recyclable metal in the production of stainless steel. Almost one-half of all nickel went into the production of stainless steels with an additional 29% in superaHoys and... 

Optical resolution is another method of producing (—)-mentho1 from racemic materials. (A)-Menthol is treated with optically active resolving agents to separate the (—)-mentho1 from the (+)-menthol, which is further processed by racemization over a nickel catalyst and recycled (156). 

Refining and Isomerization. Whatever chlorination process is used, the cmde product is separated by distillation. In successive steps, residual butadiene is stripped for recycle, impurities boiling between butadiene (—5° C) and 3,4-dichloto-l-butene [760-23-6] (123°C) are separated and discarded, the 3,4 isomer is produced, and 1,4 isomers (140—150°C) are separated from higher boiling by-products. Distillation is typically carried out continuously at reduced pressure in corrosion-resistant columns. Ferrous materials are avoided because of catalytic effects of dissolved metal as well as unacceptable corrosion rates. Nickel is satisfactory as long as the process streams are kept extremely dry. 

The reaction takes place at low temperature (40-60 °C), without any solvent, in two (or more, up to four) well-mixed reactors in series. The pressure is sufficient to maintain the reactants in the liquid phase (no gas phase). Mixing and heat removal are ensured by an external circulation loop. The two components of the catalytic system are injected separately into this reaction loop with precise flow control. The residence time could be between 5 and 10 hours. At the output of the reaction section, the effluent containing the catalyst is chemically neutralized and the catalyst residue is separated from the products by aqueous washing. The catalyst components are not recycled. Unconverted olefin and inert hydrocarbons are separated from the octenes by distillation columns. The catalytic system is sensitive to impurities that can coordinate strongly to the nickel metal center or can react with the alkylaluminium derivative (polyunsaturated hydrocarbons and polar compounds such as water). 

Reuse of waste metals generated from metal fabrication and from discarded products (scrap) can save large amounts of energy, particularly for metals that have high energy use in production, such as aluminum. The low fractions of energy used to produce metals from scrap for aluminum, certain sources of copper, and nickel show the value of recycling these metals. 

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