Solvent extraction processing arsenic wastewater in metallurgical process
The domestic metallurgical enterprises obtained the fast development in the 90 s, the rise of smelting capacity increased the demand for raw materials of copper ore concentrate.
To production needs, some enterprises to reduce the quality requirements of raw materials, especially the arsenic content in the raw material.
Cause arsenic content exceeds bid badly, the consequences are brings to the enterprise environment management difficulty, make some air emissions and wastewater discharge exceeds bid badly.
the composition of arsenic in copper smelting sewage of arsenic in copper ore concentrate with copper sulphide form, mainly tennantite sulfur and arsenic copper mine.
Arsenic mineral in the process of selecting basic does not dissolve in water and occurrence in the copper ore concentrate.
In the process of smelting, arsenic in copper ore concentrate for the most part due to the high temperature in smelting in flue gas, and exists in the form of As2O3.
And smelting gas by purification, technological process of dry absorption, transformation into sulfuric acid.
Acid production process using a turn a suction, for the most part As2O3 in flue gas into acid tail gas, the tail gas treatment system for processing and recycling, the exhaust emissions standards.
But now � � of the high cost of tail gas treatment process exists, and exhaust emission standard hard problems, so the smelter off-gas acid production enterprise mostly through technical reform as far as possible using the two turn acid absorption process, make acid tail gas emissions standard.
And As2O3 and other impurity in the flue gas is drawn into the regular dirt acid, then to deal with pollution acid, recycle the useful metal.
smelting enterprises of industrial wastewater mainly comes from the electric dust collecting ground flush water washing, acid workshop and other point of contaminated water production.
Quantity is big, complicated composition, containing the As, Cu, Pb, harmful metal ions such As zinc, Cd, need to deep processing to national standards.
arsenic wastewater treatment principle copper smelting enterprises have sewage treatment station, treatment of sulfuric acid wastewater and sewage factory production workshop.
Generally enter the factory sewage treatment station wastewater is characteristic of large quantity, composition complex.
Heavy metal ions, especially the arsenic ion, bring certain difficulty to the choice of wastewater treatment process.
Using simple lime milk neutralization process cannot ensure water quality standards.
Put into production in recent years a large copper smelting enterprises and technical transformation of environmental governance, the arsenic acid wastewater treatment adopts the lime milk and two pieces and molysite solvent extraction arsenic removal process, the production practice has proved that this technology is effective, the arsenic ion discharging standard, the other heavy metal ions can satisfy.
with extraction and iron removal of arsenic wastewater treatment process, the pros and cons of treatment effect and advanced process equipment and control facilities of reliability, using. cwl type centrifugal extraction machine as a wastewater treatment involved, for the whole process of standard operation to lay a solid foundation.
the vulcanization process sewage acid step by step, after the treatment of arsenic concentration in the reaction liquid generally below 100 mg/L, can recycle sewage useful metals in the acid, and create conditions for sewage treatment station discharging standard.
But the vulcanization process equipment investment and the processing cost is higher, high investment and high cost restrict the use of some small and medium-sized enterprises of the process.
Existing data suggest using solvent extraction method and treatment of arsenic pollution acid at a cost lower than that of the method of sulfide, has now formed test scale, believe that will soon get used in production.
copper smelting enterprises arsenic wastewater treatment using the method of sulfide and lime milk and two pieces and molysite arsenic removal process, can achieve expected goals, but there are some problems of dealing with the high cost of fouling acid treatment, subject to application of new processing technology, the current domestic existing institutions deal with arsenic pollution acid solvent extraction, its cost is lower than the method of sulfide, dirty acid material can be treated in separation and recycling, will bring obvious economic benefit.