Coal is a vital source of energy for the world. But the raw coal that comes out of a mine is not ready for use. It is a mix of coal, rock, clay, and other impurities. This is where coal processing comes in. A modern coal preparation plant (CHPP) is like a refinery for coal. It is a sophisticated facility for cleaning and sorting the coal. The goal is to create a consistent, high-quality product that burns efficiently.

In this guide, we’ll take you deep “inside the process” to show you the 4 key machines that are the pillars of a profitable sand washing operation.

This guide will walk you through the entire journey. We will show you the coal preparation process step by step. You will understand how we turn a rough, raw material from the ground into the fuel that powers our industries and lights our homes. We will also explain the critical role of each piece of equipment in this transformation.

Table of Contents

• What is Coal?
• What are Types of Coal?
• Where Can We Find it?
• What are Applications of Coal?
• What is the Whole Process of Coal From Mine to Electricity?
• How Do You Choose the Right Equipment for Each Processing Stage?
• What is the Price of a Coal Processing Plant?
• Why Choose ZONEDING?
• FAQ

What is Coal?

Coal is a combustible black or brownish-black sedimentary rock. It is a fossil fuel. It formed from the remains of plants that lived millions of years ago in swampy environments. Over time, layers of dead plant matter were buried under dirt and rock. Immense heat and pressure transformed this material into coal.

The main element in coal is carbon. It also contains hydrogen, sulfur, oxygen, and nitrogen. The energy in coal can release chemical energy from the ancient plants that absorbed sunlight. When we burn coal, this energy will go out as heat.

What are Types of Coal?

Coals are not all the same. They are classified by “rank,” which depends on how much heat and pressure the material endured. Higher rank means more carbon, more energy, and fewer impurities.

Type of Coal	Carbon Content	Energy Content	Key Characteristics
Peat	< 60%	Low	Not actually coal. It is the first step in formation.
Lignite	60-70%	Low	“Brown coal.” Crumbly, high moisture, smoky when burned.
Sub-bituminous	70-80%	Medium	A dull black color. Primarily used for electricity.
Bituminous	80-90%	High	Most abundant type. Used for electricity and steel.
Anthracite	> 90%	Very High	“Hard coal.” Lustrous, burns very cleanly and hot.

At ZONEDING, our equipment can handle all ranks of coal. We customize our coal processing solutions based on whether we are dealing with high-moisture lignite or hard anthracite.

Where Can We Find it?

Coal can be on every continent. It is located in underground layers or “seams.” These seams can be just a few centimeters or over 30 meters thick. There are two main ways to mine it:

• Surface Mining (Opencast):when the coal seam is close to the surface, giant earth-moving equipment removes the topsoil and rock (called overburden) to expose the coal. This method is generally safer and less expensive.
• Underground Mining: This method applys when the coal is deep underground. Miners use shafts and tunnels to reach the coal seams and extract the material.

The largest coal reserves are in the United States, Russia, Australia, China, and India. The location and mining method can affect the raw coal’s quality and the amount of coal processing it requires.

What are Applications of Coal?

Coal has been a cornerstone of industrial society for centuries. Its primary applications fall into a few key categories:

• Electricity Generation: This is the largest use of coal. In a power plant, coal applys to heat water into high-pressure steam. This steam spins a turbine connected to a generator, producing electricity. Coal combustion for power is a massive global industry.
• Steel Manufacturing: Coal is a key ingredient in making steel. A special type – “coking coal” or “metallurgical coal” is heated in an oxygen-free furnace to produce coke. Coke is as a fuel and a reducing agent in a blast furnace to turn iron ore into iron-the raw material of steel.
• Cement Production: Coal is also as a primary fuel in cement kilns. The intense heat from burning coal is needed to trigger the chemical reactions that transform limestone and clay into “clinker,” the main component of cement.
• Other Industrial Uses: Coal is also in manufacturing paper, chemicals, and pharmaceuticals. Specialized products derived from coal are used to make things like carbon fiber and silicon metals.

What is the Whole Process of Coal From Mine to Electricity?

Turning raw coal into electricity is a multi-stage journey. The coal preparation plant (CHPP) is where the most critical value-adding steps happen.

Here is the coal preparation process step by step:

1. Transportation and Handling

After mining, the raw coal is transported to the CHPP. This first stage is coal handling. It involves a series of conveyors, feeders, and stockpiles to move and store the raw coal efficiently and safely. Our ZONEDING heavy-duty belt conveyors and vibrating feeders aim to withstand the abrasive nature of raw coal.

2. Crushing and Sizing

The raw coal arrives in large, irregular lumps. It must be crushed to a more manageable and uniform size for efficient cleaning. This includes two stages:

• Primary Crushing: A coal crusher for power plant applications, like a heavy-duty jaw crusher or impact crusher, breaks the large lumps down to a size of around 50-100mm.
• Secondary Crushing: A roll crusher or hammer mill further reduces the coal size ,typically below 50mm.

3. Coal Cleaning (Washing)

This is the heart of the CHPP. Coal cleaning, also known as coal washing, is how you improve coal quality. The goal is to separate the valuable, low-density coal from the high-density waste rock, clay, and pyrite (which contains sulfur). This is done using processes that exploit the density difference:

• Heavy Media Separation: The crushed coal is fed into a tank containing a fluid (usually a mix of water and fine magnetite) with a specific density. The light coal floats and is skimmed off, while the heavy rock sinks.
• Jigs: A pulsating water current lifts and separates the material. The heavy refuse falls to the bottom while the lighter coal is carried away in the water flow.
• Spirals: For finer coal particles, a spiral concentrator uses a combination of gravity and centrifugal force to separate the light coal from heavy waste.

4. Dewatering and Drying

After washing, the clean coal is saturated with water. It is necessary to remove the water from the coal to increase its heating value and reduce transportation weight. This involves dewatering screens, which use vibration to shake the water off, and sometimes thermal dryers, which use heat to evaporate any remaining moisture.

5. Final Use: Pulverizing and Combustion

The clean, dry coal is then transported to the power plant. Before coal combustion, it is ground into a fine powder by a coal pulverizer. This powder, as fine as talcum powder, is then blown into the furnace. The large surface area allows it to burn almost as easily and efficiently as a gas, releasing the maximum amount of heat to create steam for electricity generation.

How Do You Choose the Right Equipment for Each Processing Stage?

Selecting the correct equipment for your coal preparation plant (CHPP) is crucial for efficiency, cost-effectiveness, and reliability. As a manufacturer of this equipment, we guide our customers through a detailed selection process.

For the Crushing Stage

You should ask: What is the maximum feed size and hardness of my raw coal? What is the required output size for the washing circuit?

• For hard, lumpy raw coal: A primary Jaw Crusher from our PE series is the most reliable choice.
• And For softer bituminous coal or secondary crushing: An Impact Crusher (PF series) or Hammer Crusher (PC series) provides a high reduction ratio and produces a more cubical product.

For the Coal Washing Stage

You should ask: What is the density difference between my coal and waste? What is the percentage of clay and fines?

• For coarse coal with a clear density difference: Heavy Media Separation (HMS) circuits or jigging systems are highly effective.
• For fine coal particles: Spiral concentrators are a low-cost, high-efficiency solution. At ZONEDING, we analyze your raw coal samples to recommend the most effective and economical washing technology.

For Handling and Dewatering

You should ask: What is my plant’s tonnage per hour? What is my final product moisture requirement?

• Conveyors and Feeders: These must be sized to handle the peak capacity of your plant without spillage. Our heavy-duty designs ensure long life even in harsh conditions.
• Dewatering Screens: Our high-frequency dewatering screens are essential for producing a transport-ready product with low moisture, which is critical for meeting customer specifications.

What is the Price of a Coal Processing Plant?

This is a common and important question. The price of a coal preparation plant (CHPP) varies significantly based on several key factors. There is no standard price list because every plant is a custom solution.

Here are the main elements that influence the final cost:

• Capacity (Tons per Hour): This is the biggest factor. A 500 TPH plant will cost substantially more than a 100 TPH plant because it requires larger, more powerful, and more numerous machines.
• Complexity of the Process: A simple plant with only crushing and screening is much cheaper than a complex plant with multi-stage washing, fines recovery, and water treatment circuits. The more you need to improve coal quality, the more sophisticated the plant becomes.
• Raw Coal Quality: Coal with high amounts of clay or fine particles requires more complex and expensive washing and recovery circuits.
• Level of Automation: A fully automated plant with a central control system (PLC) will have a higher initial cost but can reduce long-term labor costs and improve efficiency.
• Geographic Location: Logistics, local labor costs, and environmental regulations can also impact the final installed price.

As a manufacturer, ZONEDING works with clients to design a plant that meets their budget and performance goals, providing a transparent and detailed quotation.

Why Choose ZONEDING?

Choosing a supplier is as important as choosing the equipment. ZONEDING is a leading manufacturer of mineral processing equipment with a proven track record in the coal industry. We established our company in 2004 and have delivered solutions to over 120 countries.

Our key advantage is that we are a true one-stop solution provider for the entire coal preparation plant (CHPP). We design and manufacture the crushers, screens, feeders, conveyors, and washing components in our own advanced 80,000-square-meter factories. This means we have complete control over quality and ensure all components work together seamlessly.

Our team of 15 professional engineers works directly with you to analyze your coal and design a custom plant. Because we sell directly from our factory, we eliminate middlemen, offering competitive pricing without compromising on quality or service. We provide full-service support, from initial design and manufacturing to installation guidance, operator training, and reliable after-sales service.

FAQ

• What is a coal handling and preparation plant (CHPP)?
  • A CHPP is an industrial facility that processes raw coal from a mine. Its main functions are coal handling (moving and storing), crushing, sizing, and coal cleaning (washing). The goal is to remove non-combustible materials like rock and ash to produce a consistent, high-grade coal product for the market.
• Why is coal washing necessary?
  • Coal washing is essential to improve coal quality. It removes ash (rock and clay) and sulfur. This increases the coal’s energy content per ton, makes it burn more cleanly (reducing pollution like acid rain), and reduces wear and tear on boilers and furnaces in power plants. It turns a low-value raw material into a valuable, specified fuel.
• What do you do with coal ash?
  • Coal ash utilization is an important part of modern coal use. The ash collected after coal combustion (fly ash and bottom ash) is no longer seen as just waste. It is a valuable material used as a substitute for cement in concrete, as structural fill for road construction, and in the manufacturing of wallboard and bricks.
• What’s the difference between thermal coal and coking coal?
  • Thermal coal (or steam coal) is primarily used for its heating value to generate electricity. Its quality is based on energy and ash content. Coking coal (or metallurgical coal) is used to make coke for steel production. Its quality is based on its ability to form strong, porous coke when heated, which is a chemical property, not just a heating one.