Formula and preparation process of novel powder cement grinding aid

Abstract

The invention relates to the technical field of cement grinding aids, and discloses a formula and preparation process of a novel cement grinding aid which comprises the following raw materials in parts by weight: 3-5 parts of alkylol amine, 5-10 parts of potassium humate, 2-5 parts of sodium thiocyanate, 20-35 parts of anhydrous sodium sulphate, 25-35 parts of silica fume, 10-25 parts of hexavalent chromium reducing agent and 7-10 parts of stabilizer. According to the novel powder cement grinding aid, the chemical stability and the reduction efficiency are greatly improved, the defect that ferrous sulfate and manganese acetate are easy to deliquesce while the hygroscopicity of anhydrous calcium sulfate is overcome, the oxidation resistance of ferrous sulfate is greatly improved, the cement grinding time is shortened, the energy consumption is greatly reduced, the cement grinding aid has the advantages of favorable chromium removal property, favorable grinding aid property, favorable early strength and favorable chemical stability, does not contain chlorine salt, is environment-friendly, has wide application range, is worthy of wide-range popularization and use, brings great convenience to capital construction engineering in China, and greatly enhances the physical strength of the cement after being poured or completely dried.

Description

technical field [0001] The invention relates to the technical field of cement grinding aids, in particular to the formulation and preparation process of a novel powder cement grinding aid. Background technique [0002] The hexavalent chromium in cement comes from the raw materials of cement and the metal chromium or chromium compounds mixed in the process of processing. It has high solubility, strong toxicity, strong oxidizing effect, can permeate the cell membrane, and has the risk of carcinogenesis if inhaled. Contacting the skin will cause pain sensitivity, inflammation and ulcers, and in severe cases, it will cause loss of labor. When fresh concrete containing soluble hexavalent chromium comes into contact with groundwater, it will pollute the groundwater source and directly affect the cultivation of the soil and the drinking of the water source. [0003] The harmfulness of hexavalent chromium was discovered in foreign countries as early as the 1950s. In 2003, the Europ...

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Problems solved by technology

[0004] At present, cement plants generally use ferrous sulfate to reduce the content of hexavalent chromium in cement. It has many advantages such as low price and remarkable reduction effect. However, with its continuous application, it has gradually exposed the problems of poor chemical stability and large addition amount.

And stannous chloride, which also has excellent reducing effect, also limits its wide-scale use because of its high cost.

Some other single-component reducing agents, such as divalent manganese salts, polysulfide compounds, aldehyde compounds, etc., all have poor reducing effects, or are toxic and harmful, which affect the promotion of use.

[0005] In addition, the types and functions of domestic powder grinding aids are relatively single, so it is necessary to develop towards the research and development direction of high-efficiency, compound, environmentally friendly and low-cost powder grinding aids, and increase energy saving and reduction from multiple perspectives. Consumption of strength, improve cement performance

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