High-breathability lost foam coating and preparing method thereof

Abstract

The invention provides a high-breathability lost foam coating prepared through cast waste resin sand and a preparing method of the high-breathability lost foam coating. The high-breathability lost foam coating comprises the cast waste resin sand, aluminum silicon series refractory aggregate, crystalline flake graphite, polystyrene resin particles, aluminum powder, an oxidizing agent, fluoride, carbon fibers, a suspending agent, a bonding agent, a surface active agent, a defoaming agent and water. The high-breathability lost foam coating comprises 100 parts of cast waste resin sand, 60-100 parts of aluminum silicon series refractory aggregate, 5-25 parts of crystalline flake graphite, 2-6 parts of polystyrene resin particle, 1-3 parts of aluminum powder, 2-10 parts of oxidizing agent, 1-5 parts of fluoride, 1-5 parts of carbon fiber, 3-10 parts of suspending agent, 5-15 parts of bonding agent, 0.2-0.5 part of surface active agent, 0.5-1.5 parts of defoaming agent and 80-120 parts of water. The cast waste resin sand is used as the main refractory material of the lost foam coating, casting wastes are effectively utilized, the green casting and circulation sustainable principles are met, the problems of carbon defects and contraction defects of the waste resin sand lost foam coating are solved, and good application prospects are achieved.

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