Laboratory Sieve for Calcining Clay

Thursday November-27 2025  12:01:47

Laboratory Sieve for Calcining Clay is a precision sieving device used for processing clay and its calcined products. It is used in the raw material pretreatment stage and for particle size analysis of the calcined powder. The sieve mesh is made of materials such as stainless steel, possessing corrosion resistance, high strength, and the ability to withstand temperatures ≤300℃ to accommodate residual heat and potential corrosiveness of the calcined material.

Calcined clay is characterized by high hardness, increased particle brittleness, fine powder, and a tendency to generate fine dust. Therefore, the sieve mesh must be wear-resistant and have a strict particle size distribution. For fine powders, ultrasonic equipment can be used to clear blockages. The sieving particle size range is 20–500 μm, corresponding to a mesh size of 40–635. The most common sieve frame diameters are φ200 mm and φ300 mm, conforming to laboratory operating standards.

Types of Laboratory Sieve for Calcining Clay

Laboratory Sieve for Calcining Clay come in two main categories: standard laboratory sieves and ultrasonic laboratory sieves. Both dry and wet sieving methods can be used to obtain better particle size data.

Standard Laboratory Sieves: These sieves classify particles by mechanical vibration or tapping. They are suitable for sieving medium to coarse particles and general fine clay powder before and after calcination. Suitable mesh sizes are 10-200 mesh. For finer calcined clay particles, the sieve may clog during sieving, requiring cleaning with a soft brush.

Ultrasonic Laboratory Sieves: These sieves incorporate the principle of ultrasonic cleaning, generating high-frequency, low-amplitude ultrasonic vibrations. This vibration effectively breaks up agglomerates of calcined clay particles, releasing trapped fine powder and preventing particle adhesion or clogging of the mesh. Suitable for processing easily agglomerated, highly static, lightweight, or sticky calcined clay materials of 200-600 mesh.

Sieving Methods

Laboratory Sieve for Calcining Clay can employ both dry and wet sieving methods. Dry sieving is suitable for calcined clay with coarser particles and lower moisture content. Its advantages include speed and no alteration of particle structure; however, high dust levels or statically charged particles can reduce sieving efficiency. Wet sieving is more effective for extremely fine powders and easily agglomerated calcined clays. Water or dispersants are used to reduce surface tension, making it easier for particles to pass through the sieve openings. It is suitable for detecting the content of medium to extremely fine powders, but subsequent drying and weighing are required to calculate the distribution.

Sieve Aperture Table

Sieve size (US Sieve #)	Sieve aperture size (mm)	Sieve aperture size (μm)	Mesh (approximately equivalent)
4	4.75 mm	4750 μm	4 mesh
8	2.36 mm	2360 μm	8 mesh
10	2.00 mm	2000 μm	10 mesh
16	1.18 mm	1180 μm	16 mesh
20	0.850 mm	850 μm	20 mesh
30	0.600 mm	600 μm	30 mesh
40	0.425 mm	425 μm	40 mesh
50	0.300 mm	300 μm	50 mesh
60	0.250 mm	250 μm	60 mesh
70	0.212 mm	212 μm	70 mesh
100	0.150 mm	150 μm	100 mesh
140	0.106 mm	106 μm	140 mesh
200	0.075 mm	75 μm	200 mesh
230	0.063 mm	63 μm	230 mesh
325	0.045 mm	45 μm	325 mesh
400	0.038 mm	38 μm	400 mesh

The Role of Laboratory Sieve in the Calcining Clay Process

Laboratory sieves play a role at different stages of the calcining clay process. Before forging, they classify and sieve the clay; after forging, they allow for particle size analysis.

Pre-calcination: Used for particle size control and classification of raw clay. Sieving ensures that the clay raw material entering the calcining kiln has a uniform initial particle size that meets process requirements. This helps optimize heat and mass transfer during the calcination process, ensuring the uniformity of the calcination reaction and avoiding over- or under-calcination due to excessive particle size differences.

After calcination: Used for particle size analysis of the calcined clay clinker. Precise sieving determines whether the particle size distribution of the product meets the standard requirements for different applications such as coatings, fillers, and refractory materials. Sieving data serves as the basis for evaluating calcination effectiveness, adjusting parameters such as calcination temperature or time, and for product quality control and grading.

The general workflow of clay calcination

The clay calcination process includes:Natural air drying or mechanical drying of mined clay;Crushing of large clay pieces using a crusher and initial particle size control via sieving;Heat treatment at a specific temperature profile in a rotary kiln, tunnel kiln, or shuttle kiln to remove crystal water and organic matter, initiating phase transitions and altering the clay's physicochemical properties;Cooling of the calcined clinker under controlled conditions;Crushing or grinding of the cooled clinker, followed by sieving using a Laboratory Sieve for Calcining Clay to obtain the target particle size and final products of different specifications; and finally, packaging and storage.

The Laboratory Sieve for Calcining Clay is an indispensable tool for particle size control in the research and production of calcined clay. Its sieves are typically made of high-temperature resistant stainless steel, meeting the requirements of high hardness, high fine powder content, and easy clogging of calcined clay. Standard laboratory sieves are suitable for conventional sieving, while ultrasonic laboratory sieves are more suitable for high-precision, ultrafine powder testing. By selecting different screening methods such as dry screening and wet screening, and by controlling dust and implementing anti-clogging measures, the stability and consistency of calcined clay products can be improved, providing a reliable and precise raw material base for industries such as ceramics and refractory materials.