MgO-MA unburned brick for RH refining furnace and preparation method of MgO-MA unburned brick

Abstract

The invention relates to an MgO-MA unburned brick for an RH refining furnace and a preparation method of the MgO-MA unburned brick. According to the technical scheme, the MgO-MA unburned brick is prepared from the following raw materials in percentage by weight: 1-6wt% of silicon oxynitride fine powder, 10-30wt% of fused magnesite powder, 10-25wt% of magnesium aluminate spinel fine powder, 1-6wt% of aluminite powder and 1-5% of silica powder as matrix materials, and 50-65wt% of fused magnesite particles as an aggregate. The method comprises the steps of firstly mixing the matrix materials in a roller ball mill to obtain matrix fine powder; carrying out dry mixing on the aggregate in a mixing mill, adding phenolic resin which is 1-6wt% of the sum of the aggregate and the matrix powder and carrying out wet mixing; finally adding the matrix fine powder, mulling and ageing under a sealed condition; and carrying out mechanical pressing on the aged material to prepare the MgO-MA unburned brick for the RH refining furnace. The MgO-MA unburned brick is simple in synthesis process, energy-saving, environment-friendly and low in production cost; and the prepared MgO-MA unburned brick for the RH refining furnace has excellent apparent porosity, room-temperature breaking strength, room-temperature compression strength, high-temperature breaking strength and thermal shock resistance.

Description

technical field [0001] The invention belongs to the technical field of MgO-MA unfired bricks. In particular, it relates to a MgO-MA non-fired brick for an RH refining furnace and a preparation method thereof. Background technique [0002] RH refining furnace is a kind of refining equipment outside the furnace, which has been widely used and promoted because of the good cost performance of the smelted steel. [0003] At present, the main refractory materials commonly used in RH refining furnaces and RH refining furnace dip tube linings are magnesium chromium refractory materials. For example, "High-performance magnesia-aluminum-chromium composite spinel brick and its manufacturing method" (201210239826.4), discloses a high-performance magnesia-aluminum-chromium composite spinel brick for RH refining furnace dip tube and non-ferrous smelting furnace. will produce Cr 6+ , while Cr 6+ It is harmful to the human body and the environment, so replacing magnesia-chrome refractor...

AI Technical Summary

Problems solved by technology

[0004] "A preparation method of magnesia-alumina spinel brick" (201610163524.1) patented technology, by using different particle sizes of magnesia and corundum fine powder, mixing uniformly with a binder to obtain magnesia-alumina spinel brick; after 1500~1800℃ After sintering, the normal temperature compressive strength is greater than 75MPa, and the thermal shock resistance is water-cooled at 1100°C for more than 12 times. Although most of the properties are better, the process is complicated, and it needs to be sintered many times and the normal temperature compressive strength is low.

[0005] "A non-fired magnesia-alumina spinel brick" (201210261919.7) patent technology, using 80~90wt% of fused magnesia, 5~10wt% of magnesium-rich magnesia-alumina spinel, and 1~3wt of alumina micropowder %, Al-Si alloy powder is 1~3wt% and B 4 C0 is 2~0.6wt%, although many properties are better, but adding B 4 C as an antioxidant makes the cost too high, and the high temperature flexural strength is not good enough

[0006] "A high thermal shock magnesia spinel refractory material and its preparation method" (201510363696.9) patent technology, the product has been kept at 1740°C for more than 6 hours, although it has good thermal shock performance, it can reach more than 16 times in water cooling at 1100°C , but the apparent porosity is high and the compressive strength at room temperature is low