A method for one-step roasting of high-purity magnesia using magnesite concentrate

Abstract

The invention discloses a method for obtaining high purity magnesia through one-step roasting of magnesite concentrate, and belongs to the technical field of refractory material production. Low-grade magnesite flotation concentrate is used as a raw material, refined, pressed into balls and refired, and high purity magnesia with the MgO larger than or equal to 97.5% and the volume density larger than 3.2g / cm<3> is obtained. By means of the technology, the powdering problem in the magnesite roasting process is solved, the high purity magnesia ecological process is effectively simplified, the available magnesite resource range is enlarged, production energy consumption is lowered, and enterprise economic benefits can be effectively improved.

Description

technical field [0001] The invention relates to a method for using magnesite concentrate to roast high-purity magnesia in one step, and belongs to the technical field of refractory material production. Background technique [0002] Magnesite is a magnesium carbonate mineral and is the main source of magnesium. Various magnesium salt products prepared from magnesite are widely used in metallurgy, chemical industry, building materials and other industries, and are one of the important non-metallic minerals in my country. my country is rich in magnesite resources, and the ore reserves rank first in the world. However, with the continuous consumption of high-grade magnesite and the increasing demand for high-grade magnesium salt products in the market, how to improve the comprehensive utilization rate of magnesite is becoming more and more difficult. A lot of people's attention. [0003] Due to the pulverization of magnesite during the roasting process, the development of massi...

AI Technical Summary

Problems solved by technology

The two-step roasting process has serious dust pollution and high energy consumption in the process of light burning, grinding powder and briquetting; at the same time, because the light burning process cannot achieve quality improvement, the production of high-purity magnesia by the two-step roasting process also requires higher quality raw ore

The one-step roasting method of magnesite concentrate to produce high-purity magnesite mainly has two problems. One is that the magnesite is pulverized at 600-800°C during the roasting process. In severe cases, the furnace is blocked, the gas cannot be effectively circulated, and the production of normal tissues is difficult; Second, during the roasting process of magnesite, CO 2 A large amount of escaping will form porous light-burned magnesia, and one-step roasting to produce high-purity magnesia will result in a body density of less than 3.2g / cm 3 ; The invention patent realizes the rapid passage of the ore through the pulverization temperature zone through high-temperature roasting at 2100 ° C to 2200 ° C, and inhibits the pulverization of the ore; at the same time, it realizes MgO Remelted crystal density>3.2g / cm 3

[0008] In summary, the production of high-purity magnesia by magnesite flotation concentrate roasting has not been effectively solved. The present invention has developed a method for utilizing magnesite concentrate to roast high-purity magnesia in one step for the above-mentioned problems. Ore flotation concentrate (MgO≥47%), by overcoming the pulverization problem in the magnesite roasting process, the continuous and stable roasting of magnesite concentrate in the high-temperature shaft kiln is realized, and the magnesite concentrate is formed Refining-briquetting-re-burning process, MgO≥97.5%, bulk density>3.2g / cm can be obtained 3 The high-purity magnesia effectively simplifies the process flow of high-purity magnesia, expands the scope of available magnesite resources, reduces production energy consumption, and can effectively improve the economic benefits of enterprises