Coal is the most abundant fuel in the fuel market. As energy, coal is used for generating electricity. Coal is a black or brownish-black sedimentary rock that can be consumed and used to generate electricity. It is composed mostly of carbon and hydrocarbons, which contain energy that can be released through combustion.
Coal is produced by tectonic motion. The dead biotic material will have changed after a few geological processes. Coal has various types.
Coal types
The first grade is peat. Peat is considered to be a precursor of coal. It has industrial value in some countries like Ireland. In its dehydrated form, peat is a highly effective absorbent for fuel and oil spills on land and water.
Lignite, we also call brown coal. Lignite is the lowest coal because it is used to generate electricity only.
The next grade is sub-bituminous coal. It is a kind of coal between the lignite and bituminous coal. The sub-bituminous coal is primarily used for steam-electric power generation as fuel.
Bituminous coal is the common coal in the fuel market. The bituminous is used for heat and manufacturing the coke. Bituminous coal quality is different, so it needs to be sampled before pricing or ordering.
For the coal variety, different type’s coal has their unique use in the industry. How can people get coal? How is coal collected? The coal mining is also focused on many people.
Coal mining
Coal can be extracted from the earth either by surface mining or underground mining. Coal can be used for heating or other industrial processes directly. Otherwise, coal can be used to generate electricity.
- Surfacing mining
How to define the surface mining? In general, if coal is less than 61meters underground, it can be called surface mining.
- Undergrounding mining
Most of the world’s coal is buried deep underground. Underground mining, we also call deep mining. It is a process that extracts coal from deep below the Earth’s surface—may be as far as 300meters.
For coal mining, you need use many coal mining machines like the conveyor belt. This is a complicated process and you are better to find a professional team to build the coal mining plant. After coal mining this process, the next step is coal sampling.
Coal sampling
Coal sampling is an essential step for purchasing bulk coal. Why do we say that? Coal sampling aims to provide a representative sample for sample test to inspect the characters of bulk coal. The representative sample ensures the accurate characters of coal. Proper coal sampling method and sample preparation method are critical for the coal sample analysis. As the ASTM D 7430 said, there are two criteria that must be followed when sampling:
- Ensure that the sample is representative of the bulk material, which means all parts of the material being sampled must have an equal probability of being collected and becoming part of the final sample for analysis.
- Ensure that the sample does not undergo any chemical or physical changes after completion of the sampling procedure and during the storage prior to analysis.
We have mentioned that coal has various types, and coal has various physical characters, chemical properties, and the residue ash. The valuable content is the material which can produce energy. The coal from different areas and the coal mining method is different, its characters are different and the price is different. Coal sampling is a method to ensure the bulk coal price. Coal sampling system TOP SAMPLER has introduced it previously.
How is coal sample collected? Before you build your coal sampling plant, you need figure out these points:
What is your purpose to make the sample from this bulk material? What parameters do you want to figure out? The moisture content of coal or others parameters? Define what kind of bulk material you want to sample. And define the precision you required. And decide what kind of sampling method you want to choose.
Auger sampling system or the cross belt sampling system these two main sampling methods which do you want to choose.
Auger sampling method
Auger sampling equipment is suited for sampling from coal trucks and coal wagon. The key instrument is auger sampler. The auger sampler work principle is easy to understand. Auger sampler extract into the coal trucks and get a hopper raw material as a primary increment. The auger sampler parameters can be customized includes the auger diameter and the size of auger sampler.
Cross belt sampling method
Cross belt sampler is suited for the conveyor belt. In term of the moving stream, cross belt sampler is the best choice. Generally, the cross belt sampler has two main types that are head belt sampler and central belt sampler. The head belt sampler has a sample hopper. It will rotate a circle and collect a primary increment from the falling material. The speed of rotation can be customized. Central belt sampler is a kind of scrape sampler. It will collect a primary increment from the moving coal stream.
Coal preparing method
After collecting sufficient sub-samples, send these coal samples to process and make the coal analysis. Sample crushing, sample dividing, sample packing and the residue coal returns to the coal pile or coal moving stream. Besides, you may also need the solid testing drum, vibrating screen, sample crusher, etc. TOP SAMPLER supplies these coal sample preparation machines for sale. What’s more, TOP SAMPLER can customize the feasible turnkey projects according to different requirements.
After all these steps, the bulk material coal can be purchased in the market. The coal will be collected through the coal mining, coal sampling and coal analyzing these steps. If you have demand for the coal sampling machines, we are pleased to you send free quote for us!
