tailieunhanh - Extractive Metallurgy of Copper Part 5

Tham khảo tài liệu 'extractive metallurgy of copper part 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Inco Flask Smelling 97 a a water-spray evaporation cooler where the offgas is cooled from 1230 C to 80 C and where 90 of the entrained dust is removed as sludge b cyclones scrubbers and wet electrostatic precipitators c a fabric filter. The equipment is stainless steel to minimize corrosion. The offgas 60 to 75 volume so2 is pulled through the equipment by fans which push the gas onwards to a sulfuric acid plant for so2 capture. Solids from the cooler and dust removal equipment contain -35 Cu. The Cu is recovered by neutralizing and de-watering the sludge then recycling it through the concentrate dryer and flash furnace. Operation Inco flash smelting begins by heating the furnace to its operating temperature over several days. Natural gas combustion or externally heated hot air are used. Concentrate smelting is then begun achieving full smelting rate in about 8 hours. Smelting is ended by overheating the furnace tapping out all the slag by raising matte level to the slag taphole turning off the concentrate burners draining the matte as quickly as possible and allowing the furnace to cool at its natural rate. Steady operation and control Smelting consists of steadily blowing industrial oxygen and dry feed into the furnace while continuously removing offgas and intermittently tapping matte and slag. The goals of the smelting are to a smelt dry concentrate at a specified rate -1800 tonnes day b produce matte of specified composition -60 Cu c produce slag of specified composition and temperature -34 SiOj 1250 C. The furnace operator uses four main adjustable parameters to achieve these goals a dry feed rate b dry feed composition c industrial oxygen input rate d natural gas combustion rate. Coke may also be added to the furnace to supplement or replace natural gas. 98 Extractive Metallurgy of Copper Control strategy Fig. Basic Inco flash furnace control strategy entails a setting dried feed rate at its set-point value b setting industrial oxygen input