Pyrite is pyrite acid residue in the boiling temperature melting furnace after burning the product. Pyrite slag discharged only take up a lot of land, but also pollutes the environment and groundwater. According to industry analysts, cinder generally contains 30% to 50% iron and a small amount of aluminum, copper, zinc, gold, silver, such as integrated recovery will have important economic and social benefits. The main use of means in the following areas:
Iron and non-ferrous metal recycling
Slag can be used directly for iron, made after the iron ore, iron chloride pellets production and recycling non-ferrous metals. Iron slag in the iron works directly in the co-firing machine after sintering iron, iron slag required> 48%, sulfur content <1%, and mixed with a certain amount of iron ore. After the iron ore used in the past generally molten slag reduction firing magnetic residue (Fe304), and magnetic separation to obtain high-grade iron ore (iron content ≥ 58.5%), re-furnace smelting.
In recent years, through the quality control of pyrite sulfur content ≥ 35% and control of the furnace exhaust sulfur dioxide concentration of 13.3 ~ 13.5%, the discharge of the slag with magnetic iron-based, then magnetic separation to obtain concentrate, this treatment is more for the economy. Focus on recovery of non-ferrous metal chloride roasting method, points in the temperature, heat two.
Temperature chlorination roasting is the slag containing non-ferrous metals and chlorinated agent (calcium chloride) and mixing, pelletizing, drying, and rotary or shaft kiln Canon of 1 150 ℃ firing, so that non-ferrous metals to volatile chlorides , after separation of treatment and recovery, and access to quality pellets for blast furnace.
The temperature chlorination is pyrite slag, pyrite mixed with salt, then put into boiling furnace, at 600 ~ 650 ℃ temperature chlorination, sulfation roasting, make the non-ferrous metals from the slag material does not melt into fusible chloride or sulfate, extract recyclable non-ferrous metals.
Production of water purification agent
Pyrite slag can be used hydrochloric acid and sulfuric acid, respectively, the production of Fe-Al-hydroxy sulfate and aggregation purifying water purification agent. Hydrochloric acid with 15% hydrochloric acid at 60 ~ 70 ℃ leaching slag, which Fe2O3 and Al2O3 and AlCl3 reacts with hydrochloric acid FeCl3, by filtration, evaporation, drying can be obtained resin alumina iron.
Sulfuric acid is to a certain amount of slag, 20% of titanium dioxide waste sulfuric acid and 93% sulfuric acid added to the reactor, then add a small amount of MnO2, plus compressed air and stirring, maintaining the temperature, the reaction after 25 min, filtered while hot, iron solution by adding flocculant concentration after the appearance of light brown yellow liquid was finished – hydroxy ferric aggregates.
Pyrite slag utilization
Processed slag and finely ground pyrite concentrate the magnetic properties of magnetic enrichment of coal can be used as weighting agent.Pyrite residue in the reducing gas in the melt at 700 ℃ for magnetization burned by hydrochloric acid, filtration, concentration, crystallization, drying, briquetting, obtained by hydrogen reduction of iron powder can be used as welding or powder metallurgy materials. In addition pyrite slag containing non-ferrous metals, trace elements can be integrated as a fertilizer, the same effect as copper sulfate.
Tags：pyrite slag recycling 丨 11-10-13 02:56:08