Industrial Extraction Process of Chromium Carbide

Release time:

2022-06-06 13:11

Source:

Chromium carbide is widely used in the market, and its advantages in carbides are particularly prominent. How to obtain it? How is the production process? Xiao Bian found some information and learned it together. The process flow for the production of chromium carbide powder is as follows:

The carbonization temperature is 1450 ℃ ~ 1500 ℃, and the diffusion time is 45min. The ratio of raw materials is: metal chromium powder: graphite powder: binder = 86.5:13.5:3.5.

One. Process production method

1. Mixing: Add the weighed raw materials into the electric mixing drum. The feeding order is to add the graphite powder first, then add the metal chromium powder, and then add the binder. The feeding amount should be 1/3~2/5 of the mixing drum volume. The stirring time was 20~30min, and the rotation direction of the stirring drum was changed every 5min.

2. The briquette will be mixed raw material briquette. The size of the block is φ90 × 60mm, and the weight of each block is about 2.5kg. The formed material block should be handled with care, naturally dried for 48 hours, and put into a drying oven. Dry in the room, the drying temperature is 110±10 ℃, heat preservation 10h, heat up to 300 ℃, heat preservation 10h.

3. The carbonization equipment is 0.15MVA vacuum resistance furnace, which is vacuumed before power on. When the pressure in the furnace is less than 30Pa, the temperature can be increased by electricity. The input power at the beginning depends on the burnout of the heating element.

4. After the crushing and carbonization is completed, cut off the power supply for natural cooling, and continue to vacuum until the furnace temperature drops below 300 ℃, and stop the pump to break the vacuum.

II. Preparation by carbothermal reduction method: there are two reaction mechanisms

1 It can be used as an additive to cemented carbide (such as tungsten carbide-based cemented carbide grain refiner) for mining, machining, etc.

2. It can be used as a welding material additive, and the welding rod can be used for surfacing welding on the working surface of some mechanical equipment (such as coal mill, ball mill, jaw plate, etc.), which can increase the service life several times or more.

3. A large number of thermal spray materials used in metal surface protection process.

Three. Packaging and storage

Glass bottle packaging, each bottle net weight 0.5kg or 1kg, and then concentrated in the wooden box lining. Store in a cool, ventilated, dry warehouse, sealed preservation. It is not suitable for storage and transportation with inorganic acid, alkali and flammable materials. Handling should be light loading and unloading, to prevent damage to the container.

Four. Development of preparation methods

Chromium carbide powder is usually prepared industrially by mixing chromium oxide powder and carbon powder, and then carbonizing at high temperature. At present, in the preparation of chromium carbide, people have studied a variety of methods:

(1) The American company will be chromium powder and graphite powder in the argon protection atmosphere of high-energy ball milling to obtain chromium carbide, at 800 degrees C, carbonization 2h powder;

(2) Wang Zhaoquan et al. 1996 patent CN1176224A. It is proposed to successfully produce carbon-containing products by mixing Cr2O3 as chromium source and C as reducing agent in a certain proportion according to a certain technical route. The content of chromium carbide is more than 12%, and the carbonization rate is more than 99%. The process is simple, but the particle size of the raw powder is coarse, which is not conducive to the carbonization reaction. In addition, the carbonization temperature is also high, energy consumption is also large. The particle size of the product can not meet the requirements, can not achieve good corrosion inhibition effect, can not meet the industrial application.