A high-efficiency and energy-saving steel slag powder preparation method

Abstract

The invention discloses a high-efficiency and energy-saving preparation method of steel slag powder, which belongs to the field of comprehensive utilization of steelmaking waste resources and solves the technical problems of insufficient fineness of steel slag powder, high cost, easy wear of equipment and the like in the prior art. The high-efficiency and energy-saving steel slag powder of the present invention comprises the following steps: 1. Coarse crushing; 2. Roll extrusion; 3. First magnetic separation to remove iron; 4. Fine grinding. Among them, fine grinding includes four steps: grinding, drying, powder selection, and second magnetic separation to remove iron, forming a closed loop. The steel slag powder processed by the present invention has a specific surface area ≥ 450 m 2 / kg, the iron content of the by-product iron concentrate is ≥70%, the energy consumption is significantly lower than the level of the same industry, the waste gas discharge of the industrial production line meets the standard, and the waste water is zero discharge, which belongs to the environmental protection production line.

Description

technical field [0001] The invention belongs to the field of comprehensive utilization of waste resources, and relates to a preparation method for superfine grinding of steelmaking waste slag. Background technique [0002] As my country's steel production increases year by year, more and more steel slag is produced. As a waste resource, steelmaking waste slag has long been used only for simple applications such as paving roads and laying foundations or building foundation landfills. With the development of science and technology, it has been 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 steelmaking waste slag. However, due to the inclusion of ...

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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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