High-efficiency and environmentally-friendly method for producing laundry detergent powder from 4A zeolite slurry

Abstract

The invention relates to a method for producing laundry detergent powder from 4A zeolite slurry. The method comprises the steps of mixing industrial aluminium hydroxide and alkali, enabling the molar ratio of Na2O to Al2O3 to be 1: (1.0 to 2.0), enabling the content of Al2O3 to be not smaller than 50 g/L, and heating to enable the raw materials to be sufficiently dissolved to obtain a sodium aluminate solution; uniformly mixing the sodium aluminate solution and liquid soluble silicate, enabling the mass ratio of SiO2 to Al2O3 in mixed slurry to be 1.0 to 2.5, executing the steps of conventional pulpifying and crystallization, and filtering to obtain the 4A zeolite slurry; depositing the 4A zeolite slurry to the state that the solid content is not smaller than 200 g/L; preparing a laundry detergent powder raw material without alkaline components or 4A zeolite; and sufficiently and uniformly mixing the prepared 4A zeolite slurry and the prepared laundry detergent powder raw material, spraying and drying, and thus obtaining the laundry detergent powder. According to the method, a method of adding 4A zeolite into phosphate-free laundry detergent powder is changed, and the 4A zeolite is directly added in a slurry form, so that the production cost of the phosphate-free laundry detergent powder can be greatly reduced.

Description

technical field [0001] The invention relates to a method for producing washing powder, in particular to a method for producing washing powder with 4A zeolite slurry. Background technique [0002] At present, it is unavoidable to add the following raw materials in the industrial production of phosphorus-free washing powder: detergent, 4A zeolite and alkali; the above raw materials are fully mixed in an aqueous solution and spray-dried to finally obtain a finished product. Among them, 4A zeolite is used as soft water aid, and also as adsorbent, dehydrating agent and catalyst. Alkali is used to neutralize acidic detergents and adjust pH. [0003] Because the product needs to be prepared after spray drying, powdery 4A zeolite is often added to reduce excess water during production. Chinese patent CN103865678A discloses a method of adding 4A zeolite powder to the washing powder raw material and mixing it and then spray drying, but in the production process, the 4A zeolite is fi...

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Problems solved by technology

Chinese patent CN103865678A discloses a method of adding 4A zeolite powder to the washing powder raw material and mixing it and then spray drying, but in the production process, the 4A zeolite is first prepared as a powder by mixing slurry, crystallizing and spray drying , mixed in the washing powder raw material (wet material) in the later stage, and then sprayed and dried after mixing evenly, resulting in a waste of process, and the amount of water used in the preparation of 4A zeolite could not be used in the subsequent process, which also caused a waste of water resources

Patent CN103113996A discloses the process of directly mixing 4A zeolite powder and other washing powder powders in the drum to prepare washing powder, but because the powder is used, it is not easy to mix evenly, which increases labor intensity; second, it is easy to cause dust pollution , endangering the health of the operator

Patent CN102676326B discloses a method for preparing slurry detergent with 4A zeolite slurry, but the water content of slurry detergent is much higher than that of finished washing powder, so the requirements for 4A zeolite slurry are not high, allowing , bringing in more water; however, when preparing laundry detergent, the increase in moisture in the early stage will increase the cost and waste of resources in the later stage of spray drying, so it is not feasible to directly apply this process to the preparation of laundry detergent

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