The sampling process alone could be considered as a science of its own. The goal is from a large amount of material, to take a few grams of a representative sample which will be taken to our chemist for analysis.
If the sample is not representative and does not have the appropriate homogeneity then there is no reason to do any analysis as the result will be wrong. Our company has made significant investments in specialized equipment in order to be able to obtain homogeneous samples with granulators, mixers, separators, etc. which will ensure the best possible analysis.
Liquids Sampling
In order to take representative samples, proper agitation of the entire amount of liquid is something that must be done for each case. Attention should be paid to the type of tank being used as well as to the way the agitation will be done. For example, acidic corrosive liquids, such as hydrochloric acid, are so strong that even stainless steel vessels can not withstand it.
Alkaline samples are usually easier to handle, but there are several limitations. For example caustic solutions can not be stirred in aluminum tanks. It is good to contact our company to give you the right directions regarding the correct way of collection.
Usually, 100 to 500ml of sample is enough to perform several different types of analyses. Samplers must always be plastic or glass. The quantity can be measured either in Liters (L) or in kilograms (Kg). Usually measuring the weight/density in kilograms is more accurate than measuring the volume, but it is not always easy to weigh well in the whole quantity.
The final sample that our company will receive should be a clean, clear liquid without solids. Any solids should be filtered before mixing to avoid giving incorrect results in volume and / or weight measurement.
Powder – Dust Sampling
There are materials that contain metal nuggets based on alumina (aluminum oxide), silica, carbon, silicon carbide (SiC), zeolite, rocks and general materials which can be granulated / crushed into a powder. To correctly determine the percentage of metals, the entire quantity must go through a sampling process. This process is quite difficult and complicated and requires proper equipment and great care at all stages. It is understood that when a sample of a few grams represents quantities that can reach several tons then any differences can have a huge impact on the economic value of the material.
Sampling materials in powder / dust form is always a process of granulation (milling), mixing / homogenization (mixing / homogenization) and splitting. The first step in sampling is to break the materials into powder in the appropriate “mesh” granulometry (= unit of measurement size). The granulation result is then mixed so that we have good dispersion and homogeneity. After dividing the original sample into equal smaller samples and checking that it is really homogeneous then we can take our sample to the chemist for analysis.
The minimum quantity of the sample that our chemist needs for analysis is about 50gr while the ideal quantity is at least 100gr in case there is an error and the analysis must be repeated.
Salts / Crystals / Metal Pastes
Salts, crystals or metal pastes are usually in powder form with or without some amount of moisture. Each material has a specific content of basic and / or precious metals depending on their application. If there is only one type of material, then it is most likely that no sampling process is needed as all the material has the same composition.
In case there are different types then we have to choose the best and most economical way of sampling. Depending on the material, we can choose to analyze the powder after the above process (granulation, mixing and separation) or to melt all the materials in a metal alloy from where sampling is much easier.
The metal samples come from alloys in the form of bar / ingot. Attention should be paid into having proper mixing during the melting process so that the alloy is homogeneous. Each bar / ingot should have a good and smooth surface. This means that proper melting has taken place so that the alloy will be homogeneous. If there is any presence of lumps or holes, dirt or other materials then they must be cleaned before sampling.
If there is indication that there is inhomogeneity then the whole quantity should be smelted again and resampled. The easiest way of sampling is by drilling the plate with a drill at least 8mm to 10mm. It is best practice drilling as deep as possible and in different places in our alloy. We need at least 2gr per sample to be able to do analysis.
