Method for producing iron concentrate by brown hematite and siderite and reduction roaster

Abstract

The present invention discloses a method for adopting the limonite and the siderite to produce iron powder and a reduction roaster. The material adopts the limonite and the siderite or the specularite, the hematite, and the sulphuric acid slag, the inclined rotary reduction roaster is used, the pressure of the furnace chamber is 250 to 350 Pa, under the deoxidizing atmosphere, the inert solid is rotated and moved to 650 to 900 DEG C from the low temperature, and is cooled and magnetized, and lastly become the iron powder through the dressing by magnetic separation. The present invention is adopted to produce the iron powder, the resources is rich and the production cost is low, and through the utilization of the powder metallurgy art, the iron content of the iron powder is controlled and the activation energy of the iron powder is reduced, and the chemical reaction ability is increased, thereby the output of iron powder is high, the quality is good, the iron powder is loose and porous, the specific surface is big, the apparent density is large, the manufacture cost of pellets sinter and steel smelting can be reduced greatly, and the iron powder can use directly to produce iron oxide red as well as H and N synthetic iron catalyst, or produce ultrapure iron powder.

Description

technical field [0001] The present invention relates to a kind of utilizing limonite (Fe 2 o 3 .XH 2 O) and siderite (FeCO 3 ) reduction to magnetite technology and the improvement of special equipment in reduction magnetization, especially a kind of limonite (Fe 2 o 3 .X H 2 O) and siderite (FeCO 3 ) production method and reduction roasting furnace for iron fine powder, applicable to the beneficiation process that limonite and siderite are denatured into loose porous, large specific surface, finely ground into strong magnetic magnetite fine powder through reduction heat treatment, and also Works with hematite and specularite. technical background [0002] Iron concentrate powder is the main raw material for iron smelting. At present, there are two main methods for producing iron concentrate powder, one is the physical separation of magnetite, and the other is the chemical separation and purification method. Using the magnetite physical separation method to produce i...

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Problems solved by technology

Using the magnetite physical separation method to produce iron fine powder, although the process is simple and relatively easy to prepare, but because the prepared iron fine powder particles are solid flat, small specific surface area, and high impurity content, it affects powder metallurgy and iron and steel smelting quality and efficiency

The main beneficiation methods for low-grade limonite, siderite, and hematite: one is separation and enrichment by gravity separation, but due to the tight combination of impurities such as silica and iron It is obviously difficult to purify and enrich the raw ore with a grade of 30-50% to a concentrate with a grade of 30-50% or more. Even high-grade siderite cannot be smelted directly. Therefore, most low-grade components with complex Limonite and most of siderite and specularite are discarded, resulting in a waste of mineral resources; the other is chemical separation flotation, but the cost of fine grinding and chemical separation is very high, and the benefit is not very good Significant; the third is strong magnetic separation, but the effect is not obvious

Chinese patent 200510068608.9 discloses a "magnetism-preserving reduction roasting process for rhombic, brown and red mixed iron ores", using a shaft furnace with upper and lower rows of burners, under negative pressure and in a dilute reducing agent atmosphere Operation, the ore is crushed into 75-20mm particle size and loaded into the furnace from the top of the furnace. At 150°C, the attached water on the surface of the ore evaporates, dehydrates at 300-400°C, completes dehydration at 600°C, and completes dehydration at 400-400°C At 560°C, the siderite is decomposed and the hematite is reduced. After fully reacting in the decomposition and reduction extension section, the whole body of the ore block is magnetized. There is no turning, and the downward speed of the ore is difficult to control, which affects the uniformity of heating, the reduction reaction speed is different, and there are raw and over-burned phenomena; in addition, the porosity of the reduced iron powder is still poor

The currently used rotary furnace is composed of a rotary furnace body, a supporting wheel, a supporting wheel rail, and a motor. The mouth of the furnace body is open. Whether it is used for pellet sintering, lime production, etc., the working atmosphere is oxidizing or weakly oxidizing. At the same time, the cooling of mineral materials is oxidative cooling no matter in the furnace or outside the furnace, and the production of reduced iron fine powder or reduced iron powder must be roasted and cooled in a reducing or protective non-oxidizing atmosphere, so the currently used rotary kiln Not suitable for the production of iron concentrate powder

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