Process for recycling filter residues of polyaluminium chloride series coagulants

Abstract

The invention provides a process for recycling filter residues of polyaluminium chloride series coagulants. Under the condition of not adding any reaction equipment or raw materials, the filter residues are directly reused in the production process of polyaluminium chloride series products. The process comprises the steps of adding industrial hydrochloric acid or industrial synthetic hydrochloric acid to a reaction vessel, adding aluminium hydroxide under the condition of constant stirring, carrying out steam heating, controlling the reaction temperature to be 80-110 DEG C and reaction time to be 2-5 hours and cooling a reaction solution to 50-70 DEG C, adding the filter residues and calcium aluminate powder under the condition of constant stirring, adding water and controlling the flow when water is added to control the solution temperature between 80 DEG C and 100 DEG C, carrying out solution-residue separation after reaction for 2-3 hours, subpackaging and warehousing the finished product of solution and returning the filter residues to a production system to continue participating in reaction, wherein the water quantity converted from steam quantity needs to be deducted from the total water quantity when the solution temperature is controlled between 80 DEG C and 100 DEG C. The technical process is simple, is high in recycle rate of active ingredients of the filter residues and can reduce the production cost and the environmental protection pressure.

Description

technical field [0001] The invention belongs to the treatment of water, waste water, sewage or sludge. In particular, it relates to a resource recycling process of filter residue produced in the production process of water treatment agent. Background technique [0002] Coagulation is the core process of water treatment. Since the polyaluminum chloride water treatment agent with good performance was available in the 1960s, polyaluminum chloride has become the mainstream coagulant in the water treatment process, and subsequently derived A series of poly aluminum chloride series products. This series of coagulants mainly use bauxite or aluminum hydroxide, calcium aluminate powder, industrial hydrochloric acid or industrial synthetic hydrochloric acid as the main raw materials. However, regardless of whether calcium aluminate powder or bauxite is used as the main raw material, a considerable amount of filter residue will be produced during the reaction process, which brings en...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the defect that the existing technology cannot put the filter residue into production to prepare standard polyaluminum chloride products, and explore a kind of resource utilization technology of polyaluminum chloride series coagulant filter residue, without increasing equipment In the case of other raw materials, the filter residue is directly reused in the production process of polyaluminum chloride, and the existence of free acid in the early stage of the production process is used to fully react with the filter residue to recover the effective components, and explore the specific process of recycling the filter residue parameters, all indicators of the final product meet the requirements

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