High temperature rotary furnace calcination of powder

The high-temperature rotary furnace achieves uniform calcination of powder materials through the synergistic effect of rotational motion and high-temperature environment. Let’s take a detailed look at the principle and advantages of high-temperature rotary furnace calcination of powder below!

High temperature rotary furnace that can be used to calcine powders (click on the image to view product details)

1. Core working principle
Heat transfer mechanism
Heat conduction: The material comes into direct contact with the high-temperature furnace wall, and heat is transferred from the high-temperature zone to the low-temperature zone.
Convection heat transfer: High temperature gases (such as air and inert gases) flow inside the furnace and exchange heat with the surface of the material, accelerating the temperature rise.
Radiation heat transfer: The high-temperature flame or electric heating element of the furnace transfers heat to the material through radiation, ensuring uniform internal temperature.
Rotating motion: The furnace body rotates at a speed of 0.1-10 rpm to continuously roll the powder, avoid clumping, and improve the uniformity of heat treatment.

chemical reaction control
Oxidation/Reduction Reaction: Control the reaction pathway by adjusting the atmosphere (such as air oxidation or nitrogen reduction).
Crystal transformation: High temperature induced phase transition, such as the transformation of titanium dioxide from rutile phase to rutile phase.
Sintering densification: Ceramic powder undergoes necking and pore closure between particles at high temperatures, enhancing material density and strength.

2. Technical advantages
Uniformity improvement
Rotating motion continuously exposes powder particles to high temperature zones, avoiding local overheating or undercooking. For example, when calcining lithium positive electrode materials, the temperature uniformity can reach ± 5 ℃, and the crystal transformation rate is higher.

Optimization of reaction efficiency
Shorten reaction time: The stirring mechanism allows the powder to fully contact the gas, increasing the reaction rate.
Reduce energy consumption: Waste heat recovery systems (such as preheating raw materials with exhaust gas) can reduce fuel consumption.

Multi atmosphere compatibility
Supports oxidation (air), reduction (H ₂/CO), inertness (N ₂/Ar), or vacuum environments to meet different material requirements.

continuous production
The rotary compass tank separation mechanism achieves intermittent feeding and continuous calcination, resulting in higher daily output per furnace.

3. Typical application scenarios
Metallurgical industry
Zinc concentrate desulfurization and laterite nickel ore roasting.

Environmental protection field
Hazardous waste disposal: decomposition of dioxins, solidification of heavy metals, and treatment of sludge.

Preparation of new materials
Lithium battery material: Lithium carbonate is transformed into β – spodumene (1100-1200 ℃) to enhance battery performance.
Ceramic powder: nitriding, coating, purification treatment, resulting in higher product purity.

Aluminum oxide industry
Second stage calcination: dehydration at 950 ℃+crystal transformation at 1250 ℃, high content of α – Al ₂ O3, waste heat power generation recovers electrical energy per ton of product.

4. Operating standards and safety requirements
Preheating and Loading
After preheating the empty furnace to the set temperature (such as 500 ℃), evenly load the powder through the feeding port to avoid local accumulation.

atmosphere control
Oxidative calcination: Maintain an air flow rate of 2-5 L/min and oxygen content of 2% -5%.
Inert protection: First exhaust the air (blow with N ₂ for 30 minutes), then raise the temperature to the target temperature.

Speed regulation
Adjust the speed according to the properties of the material (0.5-5 rpm):
Fine particle powder: High speed (3-5 rpm) to prevent agglomeration.
Coarse particles or fragile materials: Avoid crushing at low speeds (0.5-2 rpm).

safety protection
Explosion proof design: equipped with an explosion-proof valve, which automatically releases pressure when the pressure exceeds 0.02 MPa.
Exhaust gas treatment: High temperature exhaust gas is discharged after dust removal (bag or electrostatic precipitator), with low dust concentration.
Emergency stop: When the temperature exceeds the limit (such as ± 50 ℃) or the motor malfunctions, the power will be automatically cut off and an alarm will be triggered.

5. Technological development trends
Intelligent upgrade
The digital twin system achieves virtual debugging, AI algorithm optimization of heat treatment parameters, and higher accuracy of predictive maintenance system fault warning.

Green and low-carbon technology
Hydrogen burner (CO ₂ emission reduction), plasma assisted calcination (energy consumption reduction), carbon capture system integration.

modular design
Customized furnace tubes (graphite/aluminum/stainless steel), adjustable furnace size (diameter 200-2000 mm), suitable for multiple scene requirements.

Customized multi zone rotary tube furnace with preheating (click on the image to view product details)

In general, high-temperature rotary furnaces are widely used for calcining powders. Before choosing, you can communicate with relevant technical personnel about the parameters you want, so as to customize a high-temperature rotary furnace that is more suitable for your own production or experiment!Click to learn more tube furnaces! Or click on online customer service to learn more about product information!