Efficient energy-saving steel slag powder preparation method

Abstract

The invention discloses an efficient energy-saving steel slag powder preparation method and belongs to the field of comprehensive utilization of steel making waste resources. The efficient energy-saving steel slag powder preparation method solves the technical problems that in the prior art, the fineness of steel slag powder is not high enough, cost is high, and equipment is prone to wear. The efficient energy-saving steel slag powder preparation method comprises the following steps of 1, coarse crushing, 2, roll extrusion, 3, primary magnetic separation iron removal and 4, fine grinding, wherein fine grinding comprises the four steps of grinding, drying, powder selecting and secondary magnetic separation iron removal, and a closed loop is formed. According to the steel slag powder machined by the adoption of the efficient energy-saving steel slag powder preparation method, the specific surface area is larger than or equal to 450 m<2> / kg, and the iron content of fine iron powder, as the by-product, is larger than or equal to 70%. The energy consumption is greatly lower than the level in the same industry, exhaust gas of an industrialized production line reaches the emission standard, zero discharge of wastewater is achieved, and the industrialized production line belongs to an environment-friendly type production line.

Description

Technical field [0001] The invention belongs to the field of comprehensive utilization of waste resources, and relates to a preparation method of steelmaking waste slag ultrafine crushing. Background technique [0002] As my country's steel output increases year by year, more and more steel slag is produced. As a waste resource, steel slag has long been used only for simple applications such as paving foundations or building foundation landfills. With the development of science and technology, people have found that when steelmaking waste slag is ground into steel slag powder (specific surface area ≥ 300m 2 / kg), due to the substantial increase in the activity of steel slag powder, it can be used to prepare high-strength steel slag cement. The preparation of steel slag powder is an effective way to increase the added value of steel slag and realize the high-quality utilization of steel-making waste slag. However, due to the inclusion of slag and iron in the steel slag, a dense s...

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Problems solved by technology

[0004] A kind of steel slag micropowder production process described in the above-mentioned public document CN108453111A, although realized the comprehensive utilization of resources of steel slag, still has the following problems: 1, the process of preparing steel slag micropowder by this technology must add boiling furnace slag, to improve the wearability of steel slag performance, and when the steel slag is dried, it is directly passed into the high-temperature flue gas of the boiling furnace without dust removal, and the prepared steel slag powder is not pure steel slag powder

2. This technology uses jaw crusher and rod mill to pre-grind steel slag, resulting in uneven particle size of steel slag powder after grinding, which will inevitably reduce the grinding efficiency of fine grinding process, making it difficult for the fineness of steel slag powder to meet the requirements

3. This technology uses a large rotary dryer with a diameter of Φ3.2×28m to dry steel slag. The fluidized fluidized furnace that provides high-temperature flue gas must be a large boiler, which not only greatly increases energy consumption, but also increases investment and production costs.

4. This technology uses ordinary vertical mills to finely grind steel slag. Due to the low powder selection efficiency of conventional vertical mills, the vertical grinding process takes a long time, which greatly increases the power consumption of iron slag grinding

5. Use a conventional vertical mill to finely grind steel slag, and the specific surface area of ​​the steel slag powder cannot reach 450m 2 / kg, it can only process low-quality steel slag powder for general purposes, and it is difficult to realize high-quality comprehensive utilization of steel slag

6. The 66% iron content of the by-product iron concentrate powder produced by this technology is also at a low level, which leads to an increase in the iron content in the steel slag powder, reduces the easy-grinding performance of the steel slag powder during fine grinding, increases equipment wear, and shortens the vertical mill machine service life

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