Detailed explanation of vacuum sintering process

Various powdery iron-containing raw materials are mixed with an appropriate amount of fuel and flux, and an appropriate amount of water is added. After mixing and pelletizing, the materials undergo a series of physical and chemical changes on the vacuum sintering equipment, and the mineral powder particles are bonded into blocks. process.
Vacuum sintering production process flow
Preparation of raw materials for vacuum sintering
①Iron-containing raw materials
Ore powder with high iron content and particle size <5mm, iron concentrate, blast furnace dust, rolled steel scale, steel slag, etc. Generally, iron-containing raw materials are required to be of high grade, with stable composition and few impurities.
②Flux
The flux is required to have high effective CaO content, few impurities, stable composition, about 3% water content, and more than 90% particle size less than 3mm.
Add a certain amount of dolomite to the sinter material to make the sinter contain appropriate MgO, which has a good effect on the vacuum sintering process and can be batched and mixed.
Improve ingredients and mixing
①Ingredients
Purpose of batching: to obtain sinter with stable chemical composition and physical properties to meet the requirements of blast furnace smelting. Commonly used batching methods: volumetric batching method and mass batching method.
The volumetric batching method is based on the condition that the bulk density of the material remains unchanged and the mass of the raw material is proportional to the volume. Less accurate.
The quality batching method is based on the quality of raw materials. The specific volume method is accurate and easy to implement automation.
②Mixing
Purpose of mixing: to make the composition of the sinter material uniform, with appropriate moisture content, and easy to pelletize, so as to obtain a sinter mixture with good particle size composition to ensure the quality of the sinter ore and increase the output.
Mixing operation: add water to moisten, mix and form balls.
Depending on the nature of the raw materials, two processes, primary mixing or secondary mixing, can be used.

Vacuum sintering process
The vacuum environment during vacuum sintering can prevent oxidation reactions and impurity contamination, thereby improving the purity and performance of the material.
Vacuum sintering furnaces can provide high temperature conditions, often reaching several thousand degrees Celsius. High temperature promotes the bonding and diffusion between original powder particles, achieving grain growth and densification. The vacuum sintering furnace applies high pressure to bring the powder particles into closer contact together, deforming and sintering at high temperatures. This high-pressure pressing can enhance the density and mechanical strength of the material. The vacuum sintering furnace has a precise temperature and pressure control system, which allows fine adjustment and monitoring of the sintering process. Such control helps achieve desired material properties and avoids overfiring or incomplete sintering.
In summary, the vacuum sintering furnace achieves the densification and combination of material powders by providing a vacuum environment, high-temperature operation, high-pressure pressing and sintering process control, thereby obtaining high-performance sintered materials.

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