Low-cost environment-friendly precoated sand and preparation method thereof

Abstract

The invention discloses low-cost environment-friendly precoated sand and a preparation method thereof, and particularly belongs to the technical field of precoated sand manufacturing and recycling. The low-cost environment-friendly precoated sand is prepared from the following raw materials in parts by mass: 250 to 300 parts of used precoated sand, 18 to 27 parts of a stripping auxiliary agent, 12 to 15 parts of a binder, 1.0 to 1.4 parts of a curing agent and 0.5 to 0.6 part of a lubricant, wherein the stripping auxiliary agent is prepared from lauryl acrylate, monolauryl phosphate and an acetonitrile water solution. According to the method, residual molten metal in the used sand is removed through magnetic separation, then the stripping auxiliary agent is added for vibration cracking, then the used sand is frozen, finally, a phenolic resin film on the surface of the used sand can be completely removed through simple mechanical treatment, and the regenerated sand is obtained. According to the method, waste sand resources are fully utilized, environmental pollution is reduced, and ecological balance is protected; and according to the method, the defect that the recycling and regenerating cost of the existing used precoated sand is too high is overcome, and the comprehensive cost is reduced by 15%-22% compared with the manner that new sand is completely used.

Description

technical field [0001] The invention belongs to the technical field of manufacture and recycling of coated sand, and in particular relates to a low-cost and environment-friendly coated sand and a preparation method thereof. Background technique [0002] Studies have shown that in the sand casting production process, 1-7 tons of used sand will be produced for every 1 ton of castings produced. Coated sand, as a large category of molding sand, has a large amount of use, and the used coated sand is generally treated as waste sand; this is because the surface of the used coated sand and old sand has various cured resin bonds. The curing process of this kind of resin binder is generally irreversible, so it is relatively difficult to recover this kind of old sand, the required equipment is huge and complicated, the energy consumption is high, the cost is high, and the yield of the obtained recycled coated sand is low. Application No. 200710300278.0 discloses a camshaft sand mold m...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the technical problems of high cost and low yield of existing coated sand regeneration process in the background technology, the present invention provides a low-cost environment-friendly coated sand and its preparation method, which can effectively reduce the The production cost reaches 15%-22%. In addition, the present invention effectively utilizes the discarded old sand resource and has no pollution to the environment