Slag Dryer for sale

Slag Dryer For Sale

To recycle slag produced in ore dressing or smelting industry, Zoneding Machinery develops new advanced dryer for slag drying. Zoneding slag dryer machine is commonly used in building materials, chemical industry, cement, etc. Mainly composed of rotary cylinder, lifting blades, self-cleaning device and other equipped devices, slag dryer, or slag drying machine operates stably as well as is of mature technology, high production capacity and efficiency.

√ High temperature fluidized furnace

√ Pulverized coal duster furnace 

√ Artificial coal furnace.

What is Mineral Slag?

Slag is a non-metallic byproduct created during the smelting of metals. When molten metal is separated from its ore, the impurities float to the top and are skimmed off. This molten material is then cooled to form a hard, glassy, or crystalline rock-like substance. The two most common types are:

1. Blast Furnace Slag: From iron production. When rapidly cooled with water, it forms granular, glassy pellets.
2. Steel Slag: From steelmaking in a Basic Oxygen Furnace (BOF) or Electric Arc Furnace (EAF). It is more crystalline and dense.

Why Do We Need to Dry the Mineral Slag?

Wet slag has very limited use and is expensive to transport. Drying is the essential first step to making it a marketable commodity. Drying slag:

• Enables Further Processing: Dry slag can be effectively crushed, screened, and ground into specific sizes for different applications. You cannot grind wet, sticky slag.
• Creates a Specification Product: Applications like cement production require a precise and very low moisture content.
• Reduces Transportation Costs: Water is heavy. Removing it significantly cuts shipping expenses.
• Improves Handling and Storage: Dry slag is a free-flowing material that is easy to move with conveyors and store in silos without clumping.

What are the Applications of Dried Mineral Slag?

Dried and processed slag is a valuable raw material, particularly in construction. Its applications are a key reason to invest in a slag drying process.

• Cement Production (GGBFS): Dried and finely ground granulated blast-furnace slag (GGBS) is a valuable supplementary cementitious material (SCM) that can replace a significant portion of Portland cement in concrete, making it greener and more durable.
• Road Aggregate: Crushed and dried steel slag is an extremely tough, high-friction aggregate for road base and asphalt.
• Concrete Blocks: Used as a lightweight and strong aggregate.
• Abrasives: Certain types of slag are used for sandblasting media.
• Soil Conditioner: Can be used to improve the properties of acidic soils.

What is the Process Flow of Drying Slag?

A complete slag drying process is a robust, multi-stage system designed for extreme duty:

1. Feed Preparation: Wet slag is fed from a stockpile into a hopper.
2. Crushing/Breaking Zone: The material enters the first section of the dryer, which is equipped with heavy-duty chains or hammers to break apart large, wet clumps.
3. Drying Zone: The slag then travels through the main body of the rotary dryer, where it is tumbled through a stream of hot gas.
4. Discharge: The hot, dry slag exits the dryer onto a heat-resistant conveyor.
5. Dust Collection: A heavy-duty cyclone and a high-temperature baghouse capture the fine, abrasive dust. This dust is often a valuable part of the final product.
6. Further Processing: The dried slag is then typically sent to a screening plant to be sized or to a grinding mill for GGBS production.

What is the Slag Dryer?

A slag dryer is a highly specialized type of industrial rotary dryer built to withstand the extreme abrasion and high temperatures required for this application. It is not an ordinary dryer. It is a heavy-duty machine where every component, from the steel shell to the drive system, has been reinforced and designed for a high-wear environment.

What are Different Types of Slag Dryer?

While most are rotary dryers, the design differs based on the slag type. You must never confuse a steel slag dryer with a blast furnace slag dryer.

• Steel Slag Dryer: This is a “brute force” machine. Its main design focus is on extreme abrasion resistance. Temperature control is secondary to survivability. It is overbuilt, heavy, and designed to be worn down and relined.
• Blast Furnace Slag Dryer (for GGBS): This is a “finesse” machine. While still abrasion-resistant, its primary focus is on precise temperature control. This is because overheating blast furnace slag will destroy its valuable cement-like properties. It requires more sophisticated controls and product temperature feedback.

Applications of Slag Dryer Machine

Thanks to its own cleaning device and material lifting plate, slag dryer is extensively applied to dewater wet materials with large specific gravity.

1. Slag dryer is mainly used in smelting field like iron industry for the tailings of blast furnace slag drying;
2. In cement industry, the slag dried by the slag drying machine is milled into powder and is used as the raw materials in cement and concrete production;
3. Slag dryer is also be used in building materials production and as the raw material in chemical industry.
4. Other applications: slag dryer is used for drying carbide slag, granulating slag, limestone, metal powder, clay, river sand, coal slime, sludge and other materials.

1. Blast furnace slag

Drying Requirement: Blast furnace slag is typically generated during the smelting process by water quenching and often carries a high moisture content.

Application: After drying, blast furnace slag can be used as a concrete additive, road base material, cement product, etc. Due to its higher silicon content, it can also be utilized in glass manufacturing.

2.Furnace slag

Drying Requirement: Furnace slag is typically generated during the metal smelting process, and its moisture content depends on the smelting process and cooling method. Certain types of furnace slag may require drying to reduce moisture content.

Application: After drying, furnace slag can be used in road construction, soil improvement, cement production, etc. It can also serve as railway track materials.

3.Coal gangue

Drying Requirement: Coal gangue is a byproduct generated during coal mining, with high moisture content, often requiring drying to reduce moisture levels.

Application: After drying, coal gangue can be used to manufacture bricks, tiles, coal gangue bricks, and other building materials. It can also be utilized in power generation, cement manufacturing, and other industrial applications.

4.Bauxite residue

Drying Requirement: Bauxite residue is typically generated during the extraction of aluminum, with relatively high moisture content, requiring drying treatment.

Application: After drying, bauxite residue can be used for soil improvement, mine reclamation, cement production, etc. It can also be utilized in the production of ceramics, glass, and other products.

What are Applicable Material for a Slag Dryer?

Our slag dryers are designed to process various industrial byproducts, including:

• Granulated Blast Furnace Slag
• Steel Slag (BOF and EAF)
• Foundry Slag
• Nickel Slag
• Copper Slag
• Other similar abrasive, mineral-based materials.

The Working Process of Slag Rotary Drying System

Co-current heating mainly works in slag drying process. Wet slag is transmitted into the cylinder by the feeding box and feeding conveyor. Then it is pushed back to the other end of the cylinder of the drum by spiral blades inside. The dryer is set at a certain angle. On one side, the wet slag flows down to the exit under the effect of gravity and rolling. On the other, it is brought up to the top end of the cylinder by the blades and falls into a screen to get in full touch with the scorching wind. Thanks to this repeated proceeding, wet slag is dried step by step.

Working Principle of Slag Dryer

Loading area:

After the wet slag enters the drying drum, it first enters the loading area, where the wet slag quickly contacts the high-temperature hot air and begins to evaporate its water. At the same time, under the push of the large inclination of the loading plate, the slag is not easy to adhere and smoothly transitions to the next working area.

Lifting and cleaning area:

Then the wet material enters the lifting and cleaning area, where the wet material is lifted by the lifting plate to form a curtain shape. Since the wet slag is easy to adhere to the inner wall of the drum when it falls, the equipment is designed with a cleaning device to effectively remove the adhered slag. At the same time, the cleaning device can also break up the slag blocks, increase the heat exchange area, and increase the drying speed.

Inclined loading area:

Next is the inclined loading area. In this area, the wet slag has reached a low-moisture loose state and no longer shows cohesiveness. After sufficient heat exchange, the slag reaches the required moisture content and is ready to enter the unloading area.

Unloading area:

The last is the unloading area. Here, the drum no longer has a lifting plate. The wet slag rolls and slides to the unloading port in this area to complete the entire slag drying process.

What is the Structure of a Slag Dryer?

Your dryer is not a dryer; it is a grinding mill that you feed with steel byproduct. The structure must reflect this reality.

• Full Abrasion-Resistant Lining: A standard carbon steel shell would be destroyed in 1-2 years. A proper slag dryer must have a full internal lining of bolted, replaceable AR400 (or higher) steel plates.
• Cast High-Chrome Lifters: The lifters that tumble the slag cannot be simple fabricated steel. They must be cast from high-chromium iron or a similar ultra-hard alloy to survive the grinding action.
• Inlet Crushing Zone: The first section of the dryer must be an aggressive crushing zone. Instead of simple lifters, it should be fitted with heavy-duty swing hammers or a dense curtain of chains to violently break up sticky, wet clumps before they enter the main drying zone.
• Corrosion-Resistant Feed End: Slag often contains sulfur. This creates a hot, acidic gas that can condense at the cold feed end, eating it away the steel. The feed chute and the first few feet of the dryer shell should be built from stainless steel to resist this acid corrosion.

Structural Advantages of Zoneding Slag Dryer

Slag Dryer Machine Structure 

Slag dryer is also a kind of rotary dryer, which is mainly composed of a rotating cylinder, induced draft fan, high-speed scattering equipment, lifting plates, self-cleaning device, transmission device, conveyor, hot air equipment, reducer, supporting device, sealing device and other components.

Structure of Slag Dryer

• Slag dryer can meet different particle size and moisture need of slag, fly ash and other materials.
• Large processing capacity, strong anti-overload capacity, low fuel consumption, which can reduce the drying cost.
• Concurrent flow drying design is adopted  to achieve the best drying effect. Material and heat flow enter into the drying equipment from the same side. The dryer outlet temperature is low with high thermal efficiency.
• New kind of feeding and discharging device to prevent the feeding jam, discontinuous, inhomogeneous and feeding returning phenomena, which reduces the load of the dust collecting system.
• The innovation of inner structure strengthens the cleaning and heat transfer effect of dispersed materials and eliminates the sticking phenomenon of the inner cylinder wall.

How to Prolong Slag Drying Machine Service Life

The key to extend the service life of the slag dryer is to do often maintenance and check. Based on experience, Zoneding engineers give some tips for reference.

1, Bearings take all the load of the machine. Therefore, satisfactory lubrication is much concerned with the service life. Lubricant oil infused shall be clean and the container shall be sealed well;

2, Frequently check the newly installed tyre, which is easily loosed;

3, Pay more attention to the easily-worn parts and be ready to replace those need to;

4, Pay much attention to the oil temperature of the bearing parts. Put an end to the dryer immediately, if it goes up higher. Find the cause and figure it out.

5, An impacting sound from the rotating wheels shall call your attention to stop this drying machine. Immediate check and solutions are needed.

How Does the Slag Dryer Work?

The slag is fed into the rotating drum and is immediately shattered by the chains or hammers in the inlet zone. As it moves down the drum, the cast lifters continuously cascade it through a stream of hot gas from a furnace. For GGBS production, this process is critically controlled.

The goal is not to get to 0% moisture. This is the counter-intuitive secret of GGBS production. The cement-like properties of granular blast furnace slag come from its glassy structure. If you overheat the slag (material temps over 150°C), you change its crystal structure and permanently kill its value. A perfectly dried GGBS should retain about 0.5% residual moisture. Going to zero is a waste of fuel and actively destroys your product.

What are Key Features of a Slag Dryer from ZONEDING?

At ZONEDING, we engineer our slag dryers for decades of profitable service in the harshest conditions.

• Application-Specific Design: We don’t sell a “slag dryer.” We engineer a steel slag dryer or a GGBS production dryer based on your specific material and goals.
• Extreme Abrasion Package as Standard: Our dryers include full AR400+ bolted liners and cast high-chrome lifters as a default, not an option.
• Advanced Temperature Control: For GGBS machines, our systems use precise product temperature feedback loops to protect the slag’s hydraulic properties.
• Heavy-Duty Dust Collection: We design cyclones and baghouses to handle abrasive, valuable slag dust, using hardened fan impellers and ceramic-lined components where needed.

What Is the Price of a Slag Dryer?

The cost of a slag dryer machine can range widely from $200,000 to over $3,000,000. The final price is determined by:

1. Capacity: How many tons per hour of slag need to be dried?
2. Slag Type: Is it a “brute force” steel slag dryer or a “finesse” GGBS machine with advanced controls?
3. Scope of Supply: Does the price include the feed system, dust collection, and conveyors?

A cheap slag dryer is one that lacks the necessary abrasion-resistant materials. It will fail quickly, and the cost of downtime and replacement will far exceed any initial savings.

How to Choose the Right Slag Dryer?

Choosing the right dryer begins long before you look at equipment.

1. Test Your Slag First: For steel slag, you must test it for stability. The hidden danger is “free lime” (CaO), which can cause the final product to expand and crack over time. An old-timer’s method is to boil a crushed sample in water for a few hours. If it crumbles or disintegrates, you have a free lime problem. This slag must be “aged” (left in piles exposed to weather) for months before drying.
2. Define Your Goal: Are you making road aggregate or GGBFS? The answer dictates a completely different machine design, as discussed above.
3. Demand a Wear Package: Do not even consider a dryer that does not have a detailed specification for a full, replaceable, bolted-in abrasion-resistant liner and cast alloy lifters. Ask the manufacturer for a drawing of the wear package.

How to Maintain the Slag Dryer?

Maintenance is a proactive battle against wear.

• Plan for Relining: Slag dryer maintenance is not about if you will replace liners, but when. You must perform regular internal inspections to measure wear rates and then schedule shutdowns for liner replacement.
• Inspect High-Stress Zones: The inlet crushing zone and the discharge area experience the most wear and should be inspected most frequently.
• Lubricate Everything: The massive weight of the drum and its contents puts enormous stress on the trunnion wheel bearings and the main drive. Daily lubrication is critical.
• Check Your Dust System: Regularly inspect ducts for wear, especially at elbows. Check that the fan impeller is not being eroded and that the baghouse cleaning system is functioning correctly.

General Specification