The production process of smelting of white corundum, due to the refining of alumina solution is not uniform, so the chemical composition and structure of the crystal block parts are uneven. This uneven situation is clearly visible in the broken white corundum crystal block. In the white corundum crystal block, due to the difference in appearance, structure and mineral composition, it can be divided into the following parts: the so-called upper rise, the bottom, the center, the edge and the bottom.,

The crystal block structure of white corundum is that the upper caving material is compact, porous, and the color is from light gray to dark gray, with various colors of pollution. Part of the surface is reddish brown, take the bottom is showing spongy and other grain structure, the color is rose, blue, a few are purple brown. The overall structure of white corundum is porous and dense granular structure with fine crystal. The central bulk of the white corundum crystal block is dense, mostly medium and fine crystalline. With grease luster. The color varies from purplish brown to rose brown. There are ferroalloy inclusions in the block, and light yellow in the silvery section. The edge structure of the white corundum crystal block is dense, mostly fine crystals, some places are medium, occasionally coarse crystals, the structure is not uniform, the section is rough, dull, occasionally with grease, the color is from dark brown to blue black, the bottom of the white corundum crystal block is generally dense, the structure is distributed from fine crystals to coarse crystals, mostly coarse crystals, with a large number of iron alloy inclusions of different sizes.

The structure of white corundum crystal block is very complex, is divided into 5 parts, each part of the structure, color and particle size are not the same, the study of white corundum crystal block structure will help people more clearly understand the white corundum abrasive wear resistance, self-sharpening, toughness and other properties, so as to lay the foundation for the research and development of new types of white corundum abrasive.

White corundum particle size analysis methodScreening method

Advantages: simple, intuitive, low cost of equipment, commonly used in samples greater than 40um

Disadvantages: The results are greatly affected by human factors and mesh deformation.

2. microscope (image) method

Advantages: simple, intuitive, can be morphological analysis, suitable for narrow distribution (and small particle size ratio of less than 10:1) samples.

Disadvantages: poor representativeness, analysis of samples with a wide distribution range is more troublesome, and samples less than 1um cannot be analyzed.

3. settlement method (including gravity settlement and Li Xin settlement)

Advantages: operation gradient, the instrument can run continuously, the price is low, the accuracy and repeatability are good, and the test range is wide.

Disadvantages: the test time is longer, the operation is more cumbersome.

4. resistance method.

Advantages: operation gradient can be measured the number of particles, such as the concept of clear, fast, good accuracy.

Disadvantages: It is not suitable for measuring particle samples less than 0.1um, and it is troublesome to replace the small hole tube for samples with wide particle size distribution.

V. Laser method.

Advantages: simple operation, fast test speed, wide test range, good repeatability and accuracy, online measurement and dry measurement.

Disadvantages: The results are greatly affected by the distribution model, the cost of the instrument is high, and the resolution is low.

6. electron microscopy.

Advantages: suitable for testing ultra-new particles and even nanoparticles, high resolution, can be used for morphological and structural analysis,

Disadvantages: few samples, poor representation, measurement is easily affected by human factors, and the instrument is expensive.

7. light blocking method.

Advantages: The test is convenient and fast, the number of particles in liquid or gas can be measured, and the resolution is high.

Disadvantages: It is not suitable for samples with particle size less than 1umde. It is more exquisite in system. It is only suitable for measuring dust, pollutants or diluted drugs, and not much for general powder.

8. ventilation method.

Advantages: low instrument price. There is no need to disperse the sample, and the measurable material powder can be measured.

Disadvantages: only the average particle size value can be obtained, and the particle size distribution can not be measured.

9. X-ray small angle scattering method

Particle size measurement for nanoparticles.

X. Photon correlation spectroscopy (dynamic light scattering)

Particle size measurement for nanoparticles.