Treatment of various steel industry wastewater
First, the treatment of mine wastewater Sulfide deposits under the action of oxygen and water, wherein the sulfur, iron and other elements would form sulfuric acid and metal sulfates, dissolved in water becomes acid mine drainage. For the treatment of mine acid waste water, the lime neutralization method is generally adopted. Second, the sintering plant wastewater treatment and reuse Source of wastewater Sintering plant wastewater mainly comes from wet dust removal drainage, flushing floor water and equipment cooling drainage. The wastewater pollution of the sinter plant mainly refers to wastewater containing high suspended solids. The main goal of the sinter plant wastewater treatment is to remove suspended solids. After the wastewater is precipitated and concentrated, the sludge has a high iron content and has good recovery value. 1. Advection sedimentation tank dispersion treatment process 2. Concentrated concentration tank mud bucket treatment process 3. Concentrated concentrated zipper processing technology 4. Concentrated concentrated vacuum filtration (or pressure filtration) process 5, centralized concentration and comprehensive treatment Third, the treatment and utilization of ironmaking wastewater Overview Ironworks waste generated during the production process is mainly coal gas blast furnace slag and waste washing water. The treatment technologies of ironmaking wastewater include: the removal of suspended solids; the control of temperature; the stability of water quality; the dehydration and utilization of sediment; and the repeated use of water. Treatment of blast furnace gas washing water The gas drawn from the blast furnace is called waste gas, which is first removed by gravity and then enters the washing equipment. The washing and cooling of the gas is achieved by convective contact of water and gas in the scrubber and the venturi. Due to the direct contact between water and gas, fine solid impurities in the gas enter the water, and the water temperature rises. Some of the harmful substances such as phenol and cyanide in the minerals and gas are partially dissolved into the water to form blast furnace gas washing water. 1. Lime softening-carbonization process 2, adding pharmaceutical process 3. Acidizing process 4, lime softening - pharmaceutical process Blast furnace slag wastewater treatment (slag water separation and circulation system) Blast furnace slag wastewater generally refers to wastewater generated by water quenching before furnace. After the slag water is separated, it can be circulated. 1. Slag filtration method 2, trough dehydration method (RASA Lhasa method) 3, drum dehydration method (INBA India and Pakistan) Fourth, the treatment and utilization of steelmaking wastewater Steelmaking wastewater is mainly divided into three categories: 1. The indirect cooling water of the equipment can be recycled after cooling and cooling, and it is not discharged. 2, equipment and products direct cooling wastewater is mainly characterized by a large amount of iron oxide scale and a small amount of lubricating grease, after treatment can be recycled or efflux. 3. Production process wastewater refers to converter dust removal wastewater. Converter dust removal wastewater treatment The key to solving the dust removal wastewater of the converter is the removal of suspended solids; the second is the problem of water quality stability; the third is the dewatering and recovery of sludge. 1. Coagulation and sedimentation - water stable treatment 2, magnetic coagulation sedimentation - permanent magnet descaling process 3. Magnetic coagulation sedimentation-water stabilization agent process Continuous casting machine wastewater treatment 1. Indirect cooling water for equipment (softened water system) refers to the indirect cooling water of crystallizer and other equipment; the water quality is controlled by the method of administration. 2. Direct cooling water of equipment and products (refers to the wastewater generated in the secondary cooling zone), using solid-liquid separation (precipitation), liquid-liquid separation (de-oiling), filtration, cooling, and water quality stabilization measures to achieve recycling. 3. Net circulating water system (for cooling soft water). V. Rolling mill wastewater treatment In the production of various hot-rolled and cold-rolled products, a large amount of water is required to cool and flush steel and equipment to produce waste water and waste liquid. Treatment of hot rolling wastewater The hot rolling mill wastewater mainly includes: indirect cooling circulating water (net ring water) for air coolers, oil coolers, and turbid circulating water (turbid ring water) containing iron oxide scales and oil. 1. Hot rolling wastewater treatment process 2, sinking mud treatment 3. Treatment of oily wastewater waste residue The main problems in hot rolling mill wastewater treatment are: solid-liquid separation, oil-water separation and sediment treatment. 1. One precipitation treatment; 2. Secondary precipitation treatment; 3. Precipitation-coagulation sedimentation-cooling process; 4. Precipitation-filtration-cooling process. Cold rolling wastewater treatment The cold-rolled steel must be cleaned of the surface oxide scale of the raw material, and the acid-removed iron oxide scale is used, followed by the waste acid solution and the pickling rinse water. Another type of wastewater is the emulsion-containing wastewater from the cooling rolls. In addition, zinc-plated rolled steel sheet chromium-containing waste water is generated. 1. Neutralization treatment (medication neutralization method; filtration neutralization method) 2. Emulsion wastewater treatment (chemical method; membrane separation method) Treatment and utilization of pickling waste liquid In the process of pickling steel in the steel pickling workshop, the concentration of the pickling liquid gradually decreases, so that it can no longer be used and it is necessary to discharge the waste acid to replace the new acid. This acid that cannot be used continuously is called pickling waste. 1. Recovery of sulfuric acid pickling waste liquid (1) Vacuum concentration freeze crystallization method (decompression evaporation crystallization method) (2) Acid-free freeze crystallization method (no evaporation freeze crystallization method) (3) Adding iron filings to produce ferrous sulfate (4) Natural crystallization-diffusion dialysis method (5) Polyferric sulfate 2. Recovery of hydrochloric acid pickling waste liquid (1) Spray combustion method (2) Vacuum evaporation method 3. Recovery of nitric acid-hydrofluoric acid The pickled stainless steel is a mixed acid of nitric acid-hydrofluoric acid, and the mixed acid solution is recovered by a reduced pressure evaporation method. Universal Grinder,Pharmaceutical Grinder,Herbs Universal Mill Grinder,Pharmaceutical Mill Machine Changzhou Bole Tech Co.,Ltd , https://www.boledrying.com
Wastewater treatment method
The blast furnace gas washing water treatment process mainly includes precipitation (or coagulation and sedimentation), stable water quality, cooling (there is no cooling of the top power generation facility), and sludge treatment.