High-purity Mg-Ca sand and preparation method thereof

Abstract

The invention discloses high-purity Mg-Ca sand and a preparation method thereof. The high-purity Mg-Ca sand is prepared mainly from 17 to 62% of lightly calcined dolomite, 20 to 65% of lightly calcined dolomite Mg powder, 15 to 25% of a mixture of a binder and bittern, and 2 to 5% of electric-melting zirconia. The preparation method comprises the following steps of raw material proportioning, raw material blending, ball milling, wet method-based mixing, pressing pelleting, natural drying, sintering and discharging. The high-purity Mg-Ca sand has high green-pressing ball strength, high post-sintering compactness, excellent hydration resistance, high purity and low stable zirconia content and thus a brick prepared from the high-purity Mg-Ca sand has low impurity content and excellent thermal shock resistance. The brick prepared from the high-purity Mg-Ca sand contains a large amount of CaO and thus the brick has excellent molten steel cleaning performances and is especially suitable for production of high-cleanliness steel such as stainless steel.

Description

technical field [0001] The invention relates to the field of refractory materials, in particular to a high-purity magnesia-calcium sand and a preparation method thereof. Background technique [0002] At present, the refractory raw material magnesia-calcium sand used for firing magnesia-calcium bricks in China is generally formed by light-burned magnesia powder, light-burned dolomite dry method or semi-dry method, and the selection of binders and additives is not ideal. The degree of sand density is not high, and the ball strength is not high. During the brick making process, the product volume density is not high, and the thermal shock resistance is not good. These have become bottlenecks in the process of product use, causing the product to go offline in advance. Contents of the invention [0003] The invention overcomes the disadvantages of the above-mentioned prior art, and provides a high-purity magnesia-calcium sand with high strength, high compactness after firing, ...

AI Technical Summary

Problems solved by technology

[0002] At present, the refractory raw material magnesia-calcium sand used for firing magnesia-calcium bricks in China is generally formed by light-burned magnesia powder, light-burned dolomite dry method or semi-dry method, and the selection of binders and additives is not ideal. The degree of sand density is not high, and the ball strength is not high. During the brick making process, the product volume density is not high, and the thermal shock resistance is not good.

These have become bottlenecks in the process of product use, causing the product to go offline in advance