A kind of high air permeability lost foam coating and preparation method thereof

Abstract

The invention provides a high-permeability lost foam coating prepared from cast waste resin sand and a preparation method thereof, which comprises the following components: cast waste resin sand, silicon-aluminum refractory aggregate, flake graphite, polystyrene resin particles, Aluminum powder, oxidizing agent, fluoride, carbon fiber, suspending agent, binder, surfactant, defoamer, water. Among them, 100 parts of casting waste resin sand, 60-100 parts of silicon-aluminum series refractory aggregate, 5-25 parts of flake graphite, 2-6 parts of polystyrene resin particles, 1-3 parts of aluminum powder, 2-10 parts of oxidizing agent, Fluoride 1-5 parts, carbon fiber 1-5 parts, suspending agent 3-10 parts, binder 5-15 parts, surfactant 0.2-0.5 parts, defoamer 0.5-1.5 parts, water 80-120 parts. The lost foam coating of the present invention uses casting waste resin sand as the main refractory material, effectively utilizes casting waste, conforms to the concept of "green casting" and sustainable recycling, and solves the carbon defects and shrinkage defects of the waste resin sand lost foam coating problems and has good application prospects.

Description

technical field [0001] The invention relates to the field of casting coating preparation, in particular to a high-permeability lost foam coating prepared from foundry waste resin sand. Background technique [0002] The foundry industry produces a large amount of waste sand every year. In recent years, due to the increasingly prominent environmental protection issues, many domestic foundries are facing severe environmental pressure. With the development of the industry, the foundry industry has begun to change to the direction of "green" casting, and a large number of foundries have installed casting resin sand recycling production lines. However, the treated old sand is treated in a concentrated manner, most of which are directly discharged, and a small part is used as structural filling materials for some road engineering projects, and the value of reuse is low. [0003] Foundry waste resin sand contains 60%-80% SiO 2 , 20-40% Al 2 o 3 And a small amount of other substa...

AI Technical Summary

Problems solved by technology

[0004] To sum up, under the limitation of the current technical level, the application of foundry waste resin sand in foundry coatings is limited to the production of traditional sand casting coatings, and cannot be normally used in lost foam coatings.

First of all, after the foundry waste resin sand is crushed and regenerated, the irregularity of the particles increases significantly, the bulk density increases, and the air permeability of the material plummets. Therefore, the air permeability of the coating that is directly prepared without taking other measures cannot meet the requirements of lost foam casting. requirements, will cause carbon defects in castings

Secondly, the casting waste resin sand that is only mechanically regenerated but not roasted, because the surface of the particles is covered with an incompletely decomposed resin film, under the pouring conditions, the resin film gasifies and decomposes to absorb a large amount of heat, resulting in premature cooling of the molten iron. shrinkage defect