Stainless steel dust treatment process

Abstract

The invention relates to a stainless steel dust rotary kiln direct reduction treatment process. The stainless steel dust rotary kiln direct reduction treatment process comprises the steps that (1), stainless steel dust and reducing coal are dosed and mixed according to a ratio of 100:(10-20), and granular materials with a water content of 10-12% and a particle size of 3-5mm are prepared; (2), thegranular materials are dried and preheated in a preheating zone of a rotary kiln and are entered a high-temperature reduction zone and are reduced at a temperature of 1100-1200 DEG C for 90-120 minutes, high-volatile pea coal and high-grade grain ore are injected into the rotary kiln for carbon and hydrogen combined reduction and carbon cycle oxygenation reduction in a middle-late stage of dust reduction, so that the stainless steel dust can be sufficiently reduced in the rotary kiln; and (3), high-temperature calcined materials from the rotary kiln are subjected to cooling and magnetic separation, and granular metallized products used in a power supply furnace or a converter can be obtained. According to the stainless steel dust rotary kiln direct reduction treatment process, while processing stainless steel dust from iron and steel enterprises, the iron, nickel and chromium resources in the dust mud are effectively utilized to produce high-quality metallized materials containing nickel and chromium.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and mineral engineering, and relates to a rotary kiln direct reduction treatment process of stainless steel dedusting ash. Background technique [0002] Stainless steel dedusting ash is the fine-grained furnace dust carried by the converter gas during the stainless steelmaking process. It is composed of converter feed powder and micro-particles produced by intense reaction in the high-temperature zone. The dust-removing ash particles are basically spherical. Stainless steel dust particles are small, low density, easy to float in the atmosphere after drying, and easy to form floating dust with complex composition and great harm to human body in the air. [0003] The main phases in stainless steel dust are metal iron and chromium oxides, of which iron is Fe 2 o 3 and Fe 3 o 4 Exists in the form of CrO and FeCr 2 o 4 The form of nickel exists in the form of NiO, and at the same time forms co...

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Problems solved by technology

However, there are also disadvantages that are difficult to overcome, such as large investment in project construction, thin material layer for material reduction, low metallization rate of products, and low energy utilization efficiency, which greatly limit its promotion and application in the steel industry.

(2) The rotary kiln process is a mature process technology for most domestic iron and steel plants (such as Wuhan Iron and Steel, Benxi Iron and Steel, Pingyang Iron and Steel and Xinyu Steel, etc.) to deal with zinc-containing dust. This direct reduction method has simple process, small project investment, and high production efficiency Low operating cost (no need to purchase gas fuel) and other advantages, it has certain advantages in the treatment of zinc-iron materials such as carbon steel dust removal dust in iron and steel plants, but there is a high reduction temperature when the rotary kiln process is used to process stainless steel dust removal dust , low metal recovery rate and other issues

In addition, when the reduced materials adopt the grinding and magnetic separation process, the chromium oxide contained in the sewage is likely to cause environmental pollution, resulting in difficulties in sewage treatment, which limits its popularization and application

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