Ferroalloys are mainly used in steelmaking and casting. The main ferroalloys widely used are ferrosilicon, ferrochrome, ferromanganese, ferrosilicon calcium, ferrosilicon magnesium, silicon barium, etc.
Common particle sizes of ferroalloys are 50-100mm, 10-50mm, 0-10mm, 0-2mm, etc.
The different production process requires different grain size of ferro alloy. Through the feeding machine feeding, feeding opportunity has the corresponding size requirements such as 10-50mm, too much powder will increase the material burn rate, material bigger than 50mm, is easy to plug when feeding.
Here shares the sampling and testing methods for the determination of grain size.
Terms:
- Sampling: The whole process of the sample taken for particle size inspection of ferroalloy products.
- Bulk sample: All samples taken from a batch of ferroalloys.
- Too large granularity: Material on a screen that cannot pass through a maximum X (mm) plug hole, usually indicated by +X (mm).
- Too small granularity: Material under a screen that passes through a minimum X (mm) plug hole, usually indicated by -Y (mm).
- Sieving: The operation of separating ferroalloys of different size compositions with one or more sieves according to the size composition requirements
The Place and Requirements for Ferro Alloy Particle Size Testing
The place of ferroalloy particle size testing shall be decided by the buyer and seller through negotiation. It can be at the seller’s warehouse, at the port, or at other certain places supply and demand are required.
In the presence of representatives of both parties, sampling tools, inspection instruments, and inspection sites shall be provided by the landowner
Ferro Alloy Sampling
Ferro Alloy Sampling Tools
Ferroalloys Sampling Method
In the composition of a batch of goods, according to the ferroalloy particle size composition and batch size, the supply and demand representatives agreed to determine the sampling shovel specifications. Using the sampling shovel to take samples at each site.
A batch of ferroalloys, the size of which has been determined by measurement to be too large is picked out by hand as much as possible.
Method of sampling ferroalloys from ton bags.
The whole package of ferroalloys was selected at random. Bag surface sampling or bag cut sampling.
When sampling with a sampling shovel, insert the sampling shovel diagonally into the open package at a depth of not less than 150 mm, and then remove the sample as one sample (two or more times per package, if necessary), each sample should be roughly the same amount.
When sampling with brazing, the groove of the sample should be closed first, the groove is facing up, the whole sample brazing is inserted into the open package, sampling brazing
The depth of the package should be greater than 80% of the diagonal, open the notch so that the powder can smoothly into the brazing, and then close the notch, take out the sample brazing, the brazing
As a single sample (or more than twice per piece if necessary), each sample should be taken in essentially the same quantity.
Due to the different brittleness of various ferroalloys. It cannot become a regular shape of the particle (block). The ferroalloy size needs to be measured manually.
Although manual inspection can successfully pass the maximum limit sieve, in order to prevent the side length from being too large, the particle size of various ferroalloy products is stipulated in the same direction. The length of the upper side should not exceed 1.5 times.
Consider that there is a certain amount of powder produced during transportation. A certain percentage of error is allowed for granularity reinspection in the user’s country. Ferrochrome error 2%, medium carbon ferromanganese, silicon chromium, manganese metal 4.5%, ferro silicon 5%, other ferroalloys 3%.
