At present, China has become the world’s largest consumer of iron, copper, aluminum and other metals, while most of the related minerals need to be imported from abroad. In 2012, China imported 743.6 million tons of iron ore. Copper imports totaled 7.83 million tons. In the metal ore trade, the grade of ore is an important index to determine the price. When the grade of one ton copper concentrate on the contract is written 1% higher than the actual copper grade, the price can differ by 600 yuan. Under normal conditions, the daily demand for copper materials of a large-scale smelting plant will reach several thousand tons. In order to reduce the losses of enterprises and countries, strict sampling inspection must be carried out for each batch of ore.
Ore materials are mainly transported by railway, while the railway bulk material is carried by gondola car. The dust suppressant must be sprayed on the surface of materials before transportation. When the dust suppressant is mixed with the surface material, a hard hardening layer will be formed, which makes sampling more difficult. The traditional sampling method is manual shovel sampling. Such sampling work is inefficient, the sample obtained is not representative, and it is not convenient for enterprise management. In order to ensure the efficient production, the high-quality mechanical sampling system gradually replaces the manual sampling.
Metal Material Sampling System
Sampling machines can be divided into two categories according to static and dynamic sampling methods. The dynamic sampler is mainly the cross belt sampler, and the static sampler can be divided into gantry type, bridge type and cantilever type, among which bridge type is the most widely used one. It consists of travel crane, lift crane and sampling head. Its function is to take samples from stationary trains and cars.
Top Sampler is an experienced sampling system manufacturer in China. We mainly produce the cross belt sampler and bridge type sampling system. The auger sampling system for railcar and the auger sampling system for truck produced by our company is one kind of bridge type sampling system. Both of them can be used to sample the iron ore and other minerals. They are comprised of the portal frame, travel crane, lift crane, auger sampler, automatic vehicle location, PLC control system, sample feeder, sample divider, sample crusher, sample collection system and the residue returns system.
When the truck or railcar stops at the designated place under the sampling machine according to the automatic vehicle location system, the worker will start the travel crane and lift crane by operating the PLC control system. The sampling head stops above the sampling point, then the sampler head is lowered to the material surface by the sampler head lifting system, and rotated down into the material to sample the minerals. During these processes, the selection of sampling points is a crucial part because it is related to the representativeness of samples. So how to select the sampling point and how to design the distribution of sampling point are worthy of further study.
Metal Material Sampling Points Design
Sampling method includes whole-section sampling and fixed-point sampling. The number of samples obtained from the whole-section sampling is large and the representativeness is high. However, due to the moisture content and chemical composition of materials are different at different depths in the carriage, each sampling should be taken from the material from the surface to the bottom to ensure that the sample is representative. So the efficiency of whole-section sampling is low. The fixed-point sampling can maintain the sampling points distributed randomly at any depth of materials while keeping the high working efficiency. Therefore, when sampling metal materials, we usually adopt fixed-point sampling. The auger sampling system for railcar and the auger sampling system for truck produced by our company also utilize this sampling method.
Sampling Points DesignWhen sampling, the sampling points should cover the whole carriage. In order to avoid the random sampling point focusing on a fixed area, we divide the random sampling into the following steps: in the first step, according to GB/T14206, the total number of random sampling points per vehicle is determined to be N. The second step is to divide the whole carriage equally into N pieces. The third step is to randomly determine a sampling point in each piece. In the auger sampling system for railcar and the auger sampling system for the truck, all the sampling procedure is controlled by the computer (PLC control system) like the automatic vehicle location and random sampling in any depth and full stream. It saves labor cost, realizes the full automation of sampling and ensures the representative of samples, which is a good choice for metal material sampling. If you are interested in our system, please contact us!
