Water-quenched slag silicate series coagulants and preparation method thereof

Abstract

The invention relates to water-quenched slag silicate series coagulants and a preparation method thereof, belonging to the field of purification treatment of coking wastewater and high-turbidity wastewater. The coagulants comprise the following materials in a mass ratio, water-quenched slag is more than or equal to 60 meshes, and the mass ratio of sodium carbonate to the water-quenched slag is (0.1-0.5): 1. The water-quenched slag, the sodium carbonate, sulfuric acid and sodium hydroxide are used as raw materials. The preparation method comprises the following steps of: grinding, sieving, roasting with a cosolvent, leaching in acid, washing filter residue after acid leaching, filtering and drying; leaching in alkali: leaching the washed and dried filter residue in the alkali, and filtering; and polymerizing: polymerizing the acid leach and the alkali leach in different polymerization modes and ageing to generate 3 coagulants. By adopting the method, the water-quenched slag extract is polymerized to generate the coagulants, so that a good removable effect on turbidity and chemical oxygen demand (COD) in the coking wastewater and the high-turbidity wastewater is achieved, secondary pollution-free utilization of the water-quenched slag is realized, the production cost is reduced, the treatment effect is good, high value-added utilization of industrial solid wastes is realized, and good ecological and environmental benefits are brought.

Description

technical field [0001] The invention relates to a water-quenched slag silicic acid coagulant and a preparation method thereof, belonging to the field of purification treatment of coking wastewater and high-turbidity wastewater. Background technique [0002] The water purifiers commonly used at present mainly include aluminum salts, iron salts or polymer coagulants, and there are also combinations of inorganic coagulants and organic polymer coagulants. Although these coagulants have good treatment effects, they still have certain disadvantages, such as large water content in flocs, residue after treatment, large sludge volume, and high cost. For the first time, Hasegawa Xiaoxiong and others from Nippon Waterway Machinery Co., Ltd. produced polysilicic acid with water glass and sulfuric acid, and then added aluminum salts and iron salts to silicic acid to produce polyaluminum silicate or polysilicate iron. The polysilicate inorganic polymer coagulant combines the bonding, agg...

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Problems solved by technology

(4) Chinese patent application, application number: 200710175228.4, name: a water treatment agent prepared from blast furnace slag and its preparation method. (5) Chinese patent application, application number: 200710018532.8, name: a method for producing coagulant for water treatment with coal gangue, which is obtained by using coal gangue through processes including calcination, It is prepared in 28 steps such as acid leaching, water washing, alkalization, etc., but there is no specific example for the treatment of wastewater and the steps are complicated; (6) European patent, patent number: 169430, name: clarification of colored wastewater, Use alumina waste slag as flocculant, but no detailed preparation process

[0005] From the existing technologies found above, it can be seen that there has been some research on the preparation of polysilicate coagulants by using solid waste, but the preparation technology is not perfect enough.

Therefore, there are problems of insufficient utilization to varying degrees. For example, some coagulants prepared from industrial solid waste can only treat a specific wastewater, some coagulants can only treat a specific pollutant index, and some coagulants can only treat a specific pollutant index. Oxidants need to be added during the treatment process, and some chemicals (stabilizers) need to be added to make the price of the finished product high and the operating cost high

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