Nickel contamination

From current production and metal types, the pyrometallurgical is the main method. The non-ferrous metal smelting method can basically be divided into three categories, the first category is a sulfide mineral raw materials for sulfur smelting, copper, nickel metal belonging to this category; second category is the sulfide mineral raw materials before roasting or sintering production of metal, carbon thermal reduction, zinc, lead, antimony metal belonging to this category; sulphide ore after roasting or oxide ore with sulfuric acid solvent extraction and electricity quadrature method to extract metals from solution, a metal belonging to the type of smelting methods are mainly of zinc, cadmium, nickel, cobalt, aluminum. The copper, lead smelter production of gold, silver anode mud still using pyrometallurgical processes, general anode slime treatment including decopperization selenium, restore your lead smelting and refining silver electrolysis, gold electrolysis and other processes. Lead anode mud by direct smelting, electrolysis or off selenium and copper removal copper anode mud mixed processing.

Pyrometallurgical as the backbone processes of China's major non-ferrous smelter, grouped metallurgical production process, planning, directing, coordinating, and control and management. Smelting production were in high temperature, high pressure, toxic, corrosive environment, to ensure the safety of operating personnel and equipment, we must pay special attention to the implementation of the security measures, and efforts to improve the level of mechanization and automation. Metallurgical industry is also the most polluting industries, waste, waste water, waste gas, easy to pollute the environment and destroy the ecological balance in the non-ferrous metal production directionally to environmental emissions, it should have the "three wastes" treatment project and utilization, as well as noise, vibration, odor, radiation and thermal pollution, destruction of the ecological balance, causing environmental pollution and harmful to people's health and biological growth.

Nickel pollution is the environmental pollution caused by nickel and its compounds. While nickel ore smelting and iron and steel smelting, a part of power slag with the air into the atmosphere. Nickel and its compounds in the calcination process also discharged, mainly water-insoluble nickel sulfide (N iS), nickel oxide the (N IO), the metallic nickel dust, become the atmospheric particles. When the heating nickel powder was encountered the combustion of carbon monoxide will generate volatile, a virulent carcinogen nickel carbonyl [N i (CO) 4]. Refined nickel workers exposed to a higher risk of nasal cancer and lung cancer incidence. Nickel plating industry, machinery manufacturing, metal processing industry’s wastewater often contains nickel, commonly used soda to treat industrial wastewater it generates nickel hydroxide [N i (OH) 2] precipitation and removed. Nickel enrichment in the soil, settlement of atmospheric particulate matter containing nickel, nickel-containing wastewater irrigation, animal and plant debris rotting, are soil weathering of rocks and other sources of nickel. Plant growth absorbs nickel in the soil. The highest nickel content of the plant is green vegetables and tobacco, up to 1.5 3 ppm. The critical concentration of nickel toxicity on rice is 20ppm. In Chinese, the maximum allowable concentration of nickel carbonyl require 0.001mg/m3, the nickel surface water maximum allowable concentration is 0.5 mg / L.

Source:http://www.mhcmp.com