Method for preparing sintered magnesia from granular magnesite by one-step

Abstract

The invention discloses a method for preparing sintered magnesite from granular magnesite by one-step, and relates to a method for preparing sintered magnesite, and the method comprises the steps of pretreatment of magnesite raw materials, preheating, reburning, heat recovery, CO2 capture, flue gas purification and the like. The core thought of the method is that the small-particle-size magnesitetransfers heat and discharges CO2 more quickly, and the problems that blocky magnesite used in a traditional shaft kiln and an electric melting furnace transfers heat difficultly, the external temperature is higher than the internal temperature, accordingly, an external crystal form is converted into a compact structure firstly, and internal gas is difficult to discharge are solved. By utilizing the characteristics of high heat exchange rate, high yield, uniform particle heating and the like of the fluidized bed / moving bed, compared with the traditional reburning technology, the method greatlylowers the reburning temperature and shortens the reburning time, thereby enhancing the treatment capacity of the system and lowering the production cost of the sintered magnesia. Moreover, the method also solves the problem that the traditional shaft kiln and electric melting furnace process cannot use the powder magnesite, and improves the utilization rate of magnesite resources.

Description

technical field [0001] The invention relates to a method for preparing sintered magnesite, in particular to a method for preparing sintered magnesite in one step from powdery magnesite. Background technique [0002] Magnesite is a mineral resource composed of magnesium carbonate as the main mineral. China's magnesite reserves are about 3 billion tons, ranking first in the world, mainly distributed in Liaoning and Shandong provinces, of which Liaoning accounts for 90% above. The products of magnesite calcined and melted at different temperatures are light-burned magnesia, heavy-burned magnesia and fused magnesia. Among them, dead-burned magnesia (also known as sintered magnesia) is an important raw material for refractory materials. It is widely used in iron and steel metallurgy, building materials, non-ferrous metal smelting and other high-temperature industries, accounting for more than 40% of the entire magnesia refractories. Technological developments in these high-temp...

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Problems solved by technology

However, this technology has high requirements on the quality of magnesite raw materials, and only lumpy high-quality raw materials can be used. A large number of powdery and medium-low-quality magnesite resources are discarded, and the reburning in the shaft kiln requires high temperature and long time , high energy consumption, low output of dry briquetting equipment, and serious dust pollution

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