dry magnetic separator
PTMS magnetic separation
what is magnetic separation used for？
1. What is powder? The purpose of powdering?
A: Powder: A collection of large solid particles, and there is a proper force between the particles of the aggregate.
The purpose of powdering:
1) increase the speed of physical and chemical reactions;
2) Conducive to uniform mixing and promote homogenization of the product;
3) increase the density of the product;
4) Make the particles fluid, which is convenient for feeding control and transportation;
5) Facilitate the separation of different components.
2. What are the methods for representing a single particle? How are they defined? A: The "calculus diameter" often has four categories: three-axis diameter, ball equivalent diameter, round equivalent diameter and statistical diameter.
1 Triaxial diameter: A rectangular parallelepiped (external cuboid) with a minimum volume can fit into a particle. The size of the particles is defined by the length L, the width b, and the height t of the rectangular parallelepiped.
2 equal volume ball equivalent diameter: diameter of the ball with the same volume of the particle; equal surface area ball equivalent diameter: smuggling of the ball with the same surface area of the particle; equal surface area ball equivalent diameter: diameter of the ball with the surface area of the particle. 3 round equivalent diameter: The granularity is expressed by the smuggling of a circle having the same property as the contour of the particle projection.
4 statistical average diameter: is the linearity measured parallel to a certain direction (using a microscope), also known as the orientation diameter. 3. What are the methods for expressing the average particle size?
1 arithmetic mean particle size 2 geometric mean particle size 3 harmonic mean particle size 4 average area diameter 5 average volume diameter 6 length average diameter 7 area average diameter 8 volume average diameter
4. How to express the particle size of the powder? And explain its physical meaning?
Frequency distribution
Abscissa: granule size at each grain level ordinate: percentage of particles at a certain grain level Meaning: The percentage of particles in any particle size interval is equal to the area under the curve at the interval below the total area under the curve.
(2) Cumulative distribution
Abscissa: indicates the particle size; ordinate F (%): the number of particles or mass percentage of particles below a certain Di
Meaning: The cumulative amount of 50% of the particle size and the percentage between any two particle sizes; greater than or less than the percentage of particles of a certain size.
5. What are the methods for determining the particle size distribution of powder? What is the measurement reference and measurement range?
Method: 1 sieving method 2 sedimentation method 3 microscopy (including optical microscope and electron microscope) 4 Coulter counter and 5 laser particle size analyzer
1) Sieving method: The sieving method obtains a particle size distribution based on weight. Scope of application: loose materials with a particle size of less than 100 nm and greater than 0.038 mm.
2) Microscopy: Optical microscopy is generally suitable for particles larger than 1 um, and the particle size measured by electron microscopy can be as small as 0.001 um.
3) Sedimentation method: a method of sedimenting particles in a suitable medium and measuring the particle size according to the sedimentation speed. The theoretical basis is Stoke's theory.
4) Coulter counter: particle volume, voltage pulse. Its accuracy depends on the number of particles being counted. The range is: 05~200um
5) Laser particle size analyzer: based on two assumptions: (1) the particles are spherical; (2) the number of particles is small.
6. What are the methods for statistical granularity when measuring particle size with an optical microscope?
A. Point method: divide the field of view into a grid, and measure the particles falling on the intersection of the grid. At this time, a grid eyepiece is needed;
B. Line method: A number of equidistant parallel lines are divided in the field of view to measure all the particles falling on the line.
C. Band method: A band is defined in the field of view. All particles in the band are determined. The bandwidth must be larger than the maximum diameter of the particles in the field of view. The middle part containing more particles is selected.
