Impurity elements in quartz sand will significantly affect the performance of timely products, among which transition metals such as iron will affect the light transmittance and conductivity of timely products; The high content of alkali metal impurities such as potassium and sodium will reduce the high temperature resistance of timely products, and then affect their thermal stability and optical properties. To obtain ultra-high quality quartz sand, it must be purified.
Pickling is an important step in the purification of timely ore. The mineral processing and purification can be realized by using the characteristics of insoluble in acid and soluble in other impurity minerals. Commonly used acids include sulfuric acid, hydrochloric acid and hydrofluoric acid.
However, although the removal rate of impurities in acid-washed quartz sand is high, improper treatment of wastewater will have a serious impact on the environment and soil. The pickling waste liquid contains a lot of H+ and F- plasma. If discharged directly without treatment, it will easily lead to serious consequences such as fluorine pollution, underground pipeline corrosion and groundwater pollution.
The following introduces several common treatment processes of quartz sand pickling waste liquid:
(1) Neutralization and precipitation process
In time, the pickling waste liquid enters the regulating tank through the drainage pipeline to fully regulate the water quality and quantity of the pickling waste liquid. The adjusted wastewater is lifted to the acid-base reaction tank by the water pump, and alkaline substances (such as caustic soda, sodium bicarbonate, lime, etc.). ) and pickling waste liquid are neutralized, and stirred while adding. After acid-base neutralization for a period of time, the supernatant of the reaction tank overflows to the sedimentation tank, the water quality is detected after sedimentation, and it is discharged or reused after reaching the standard.
(2) neutralization+precipitation+flocculation+filter pressing dehydration process
The pickling wastewater is directly discharged into the regulating tank, and a perforated aeration pipe is arranged in the regulating tank to make the wastewater mix evenly. The lift pump lifts the wastewater from the regulating tank to the batching tank for the first-order neutralization reaction, so as to remove most pollutants in the wastewater.
The wastewater sludge after neutralization reaction is precipitated in the batching pool, and the precipitated wastewater continues to undergo secondary coagulation reaction in the batching pool, so as to completely remove the pollutants in the wastewater and ensure the standard discharge. After coagulation, the soluble pollutants in wastewater are completely removed, and the suspended solids are treated in the sand filtration process.
(3) neutralization+pressure filtration dehydration+multistage filtration+reverse osmosis process
The timely pickling wastewater first enters the regulating sedimentation tank, and lime water is added to adjust the PH value to 8.5~9.5. After a period of reaction, flocculant is added to coagulate impurities and sludge in water, which plays a better role in solid-liquid separation. The separated sludge enters the sludge pool, and is dehydrated by the plate-and-frame filter press and transported abroad.
The supernatant of the regulating sedimentation tank is lifted by the raw water pump, then passes through the quartz sand filter and the activated carbon filter, then enters the security filter, and then enters the reverse osmosis membrane group after being pressurized by the high-pressure pump. The produced concentrated water returns to the regulating sedimentation tank, and the product water enters the recycling tank for recycling or discharge.
? (4) Haipu special adsorption technology
Jiangsu haipu functional materials co., ltd is located in Suzhou industrial park. It is a national high-tech enterprise with special adsorbents and catalysts as its core technologies, and supports the application of process development, technical services and project implementation. , to solve related environmental problems for customers.
Jiangsu Haipu Functional Materials Co., Ltd. has a leading technical level in adsorption material treatment, and the supporting adsorption treatment process is efficient and stable, which has solved many environmental protection problems for many leading enterprises in domestic industries.
The basic principle of Haipu special adsorption technology is to use the adsorption properties of special adsorption materials to adsorb and enrich iron, calcium and magnesium ions in waste acid into adsorption materials, so as to reduce the content of adsorbed acid ions and meet the requirements of customers. After the adsorption is saturated, the adsorption material is desorbed, so that the adsorption material is regenerated, and the adsorption is continued again, and so on.
The process flow is shown in figure 1- 1. The wastewater is first filtered to intercept suspended solids and fine particles, so as to prevent impurities from entering the adsorption materials and affecting the adsorption performance. The filtered wastewater enters an adsorption tower filled with special adsorption materials for adsorption, and after adsorption saturation, the adsorption materials are desorbed and regenerated, and the regenerated adsorption materials can be reused. The adsorbed acid is recovered by the customer, and the high-concentration desorption solution is treated by the customer.
Figure 1- 1 process flow chart
Scope of application Quartz sand pickling wastewater;
Adsorption treatment case: Our company has carried out adsorption and desorption experiments on several batches of materials sampled at a project site. The specific experimental results and data as well as the comparison chart before and after treatment are as follows:
Case 1? Inlet and outlet data of adsorbed water
Fig. 2- 1 schematic diagram of waste acid adsorption
Advantages: 1 The problem of waste acid treatment in enterprises is solved, and the adsorbed acid can be recycled to ensure the sustainable development of enterprises, which has great economic and environmental benefits;
2. The special adsorption material has high adsorption capacity and concentration rate, less equipment investment and low operating cost;
3. Automatic control, convenient operation, convenient maintenance and long service life;
4. The technological process is simple and reliable, and the occupied area is small.