High fire-resistant molding sand for casting and preparation method thereof

Abstract

The invention discloses high fire-resistant molding sand for casting and a preparation method thereof. The high fire-resistant molding sand for casting comprises the following raw materials in parts by weight: 60-80 parts of fused ceramsite, 20-30 parts of mullite, 10-15 parts of corundum powder, 5-10 parts of nanometer boron nitride, 3-6 parts of light magnesium oxide, 4-8 parts of kaolin, 2-4 parts of illite, 3-5 parts of modified water glass, 1.5-2.5 parts of asphalt, 1-2 parts of polytetrafluoroethylene micro powder, 2-3 parts of polyvinylpyrrolidone and 4-8 parts of water. The high fire-resistant molding sand for casting has high degree of fire resistance, good air permeability, good filling ability and good collapsibility, is difficult to break and high in repeated utilization rate, does not generate dust and cause siliceous dust damage and belongs to the green and environment-friendly molding sand for casting. Castings produced by using the molding sand are high in size precision and have few cracks and surface detects, and the rate of finished products of the castings is high.

Description

technical field [0001] The invention relates to high refractory casting sand and a preparation method thereof, belonging to the technical field of molding sand. Background technique [0002] In the past, clay molding sand was used in the production of large and medium-sized castings. After the mold was made, it was sent to a drying furnace for drying. The production cycle was long, the precision of the castings was poor, and the working conditions were poor, which was far from meeting the needs of production development. Sodium silicate sand has become one of the fastest-growing types of molding sand in recent decades due to its high fluidity, high compaction rate, fast hardening, high casting precision, wide source, low price, and environmental protection. At present, most steel castings and large iron castings are produced by the water glass sand process. Although the water glass sand has many advantages, the molding sand is prone to expansion and breakage under high tempe...

AI Technical Summary

Problems solved by technology

At present, most steel castings and large iron castings are produced by the water glass sand process. Although the water glass sand has many advantages, the molding sand is prone to expansion and breakage under high temperature conditions, which affects the casting of the castings.