Quartz sand purification process without washing procedure

Abstract

The invention relates to a quartz sand purification process without a washing procedure, which comprises the steps of deacidifying acid-washed and purified quartz sand until the mass of acid liquor in the quartz sand is less than 10%, feeding the deacidified quartz sand into a fluidized bed dryer, and drying at the temperature of 350-750 DEG C under a hot air condition, and cooling the dried quartz sand material to obtain the high-purity quartz sand material. According to the method, the washing procedure is omitted, a large amount of environmental protection and production investment are saved, the water utilization and wastewater treatment operation cost is saved, the production cost is reduced, and meanwhile, the impurity removal effect can be further achieved in the fluidized bed drying process.

Description

technical field [0001] The invention relates to a quartz sand purification process method without a water washing process, belonging to the technical fields of inorganic chemical industry, energy saving and environmental protection and waste utilization. Background technique [0002] At present, the purification process of quartz sand in my country is inseparable from the basic processes of acid washing, deacidification, water washing and dehydration of quartz sand. In particular: in the pickling process, in order to improve the obvious pickling effect, everyone uses acid solutions such as hydrochloric acid + fluoric acid or fluoric acid + oxalic acid for heating and pickling, and after pickling, the acid solution is removed. The recycled water after recycling is washed, and then the dehydrated quartz sand is dried, cooled, magnetically separated, screened, colored, and packaged to produce different grades of quartz sand products according to different customer needs and use...

AI Technical Summary

Problems solved by technology

According to the data accumulated in many years of production, for every ton of quartz sand product purified by pickling, the washing process will produce 4-10 tons of acid-containing wastewater, and the washing time will take about 0.5-1 hour, and some will take longer ; And it will cost a lot of money to build a set of huge water treatment facilities to deal with these acid-containing wastewater. This facility not only has high operating costs, but also produces a certain amount of toxic and harmful salt-containing waste residues

According to environmental protection laws and regulations, only after the treated wastewater reaches the national discharge standard can a small part of it, that is, about 10%, be discharged to the outside within the scope of the permit, and most of it, that is, about 90%, must be recycled. To strictly control the fluoride ions not to exceed the standard, a certain amount of calcium chloride solution needs to be added, so that there is often a certain amount of calcium chloride in the circulating water, which brings certain hidden dangers to the quality of quartz sand products