Lithium Ore Rotary Kiln 5TPH-200TPH Capacity High Throughput

Lithium Ore Rotary Kiln

1.Product Introduction

A lithium ore rotary kiln is a critical thermal processing unit used in the processing of lithium ores. Its primary function is the high-temperature roasting of lithium-bearing minerals, such as spodumene, to achieve a crystal phase transformation. This process prepares the material for subsequent acidification, leaching, and the production of lithium salts (such as lithium sulfate, lithium carbonate, and lithium hydroxide)

2.Application

1. Spodumene Transformation Roasting This is the most prevalent application. Spodumene concentrate is roasted at 1050-1250 C to convert it from alpha-type to a porous beta-type. This results in an approximate 30% volume expansion, significantly boosting the lithium leaching rate in the subsequent acid-leaching stage from roughly 40% to over 90%. This process is a critical front-end step for producing battery-grade lithium carbonate or lithium hydroxide. 
2. Sulphation Roasting Following transformation roasting, the material is mixed with sulfuric acid and fed into the rotary kiln for a sulphation reaction at 250-300 C. This generates soluble lithium sulfate, laying the foundation for water leaching, purification, and precipitation to produce lithium carbonate. 
3. Lepidolite Processing In certain processes, the rotary kiln is utilized to decompose the mineral structure of lepidolite to release lithium elements, making it suitable for processing mica-type lithium ores. 
4. Purification of Crude Lithium Carbonate from Salt Lakes For crude lithium carbonate sourced from salt lakes, multi-layer sleeve rotary kilns are employed. Hydrates are decomposed at a low-temperature stage (650-800 C), followed by a high-temperature stage (1000-1100 C) to remove impurities like magnesium and boron, ultimately yielding battery-grade products with 99.5% purity. 5. Other Mineral Processing Rotary kiln technology also extends to the roasting and activation of minerals such as tantalum-niobium and rare earth ores to improve subsequent leaching efficiency.

3.Working Principle

1. Structure and Material Movement .

The rotary kiln is a large, slightly inclined rotating cylinder. Raw lithium ore is fed into the kiln at the higher end (the tail). Due to the kiln's inclination and continuous slow rotation, the material tumbles circumferentially while moving gradually along the axis from the high end to the low end (the kiln head). This compound movement ensures that the material is heated uniformly and reacts fully within the kiln. 

2. High-Temperature Calcination Process Fuel (such as coal or natural gas) is combusted at the kiln head, generating a high-temperature airflow (typically around 1000 C). The high-temperature gas and the material maintain counter-current contact—the hot air flows from the head to the tail, while the material moves from the tail to the head. This counter-current design optimizes heat utilization, allowing the material to sequentially undergo preheating, calcination (the primary reaction stage), and cooling as it advances.

3. Core Chemical Reaction For spodumene (LiAlSi2O6), the primary objective is to complete the phase transformation from the stable alpha-type to the highly reactive beta-type. This transformation typically occurs between 950-1100 C, during which the crystal structure shifts from a monoclinic to a tetragonal system. The resulting 30% volume expansion disrupts the dense structure, significantly increasing the lithium leaching rate during subsequent acid or alkaline leaching. Simultaneously, associated impurity minerals (such as mica and feldspar) partially decompose, minimizing interference with downstream processes.

4. Heat Exchange and Energy Recovery Modern lithium rotary kiln systems are generally equipped with preheaters and coolers. High-temperature flue gas discharged from the kiln tail is used to preheat incoming raw materials, reducing energy consumption. Meanwhile, the high-temperature material exiting the kiln head enters a cooler for rapid quenching. This not only preserves the reactivity of the product but also recovers heat to be reused as secondary air for the kiln head, further improving thermal efficiency.

5. Intelligent Control Advanced rotary kiln systems feature wireless temperature monitoring and intelligent variable-speed control systems. This allows operators to remotely adjust kiln conditions in real-time, ensuring precise control over calcination temperatures and material residence time, thereby maximizing lithium recovery rates.

4.Advantages

1. High Throughput and Continuous Production The rotary kiln operates in a continuous mode with a processing capacity ranging from 500 to 5,000 tons per day, making it ideal for large-scale lithium projects. Its open calcination design ensures smooth airflow and uniform material tumbling. This balanced heating effectively controls under-firing and over-firing rates, ensuring product stability and consistency.

2. Excellent Energy Saving and Waste Heat Recovery By configuring vertical preheaters and coolers, the system fully utilizes high-temperature flue gas (300-400 C) from the kiln tail to preheat raw materials. Furthermore, hot air generated during material cooling is recycled as secondary air, significantly reducing heat consumption per unit. Some designs even utilize waste heat for power generation. While absolute energy consumption is high, system integration optimizes total energy use to approximately 80-120 kg of standard coal per ton of ore, drastically lowering overall costs.

3. Strong Adaptability and Mature Technology The equipment can process various lithium resources, including spodumene and lepidolite, and couples effectively with different extraction methods such as the sulfuric acid and sintering processes. Kiln temperatures can be precisely controlled (e.g., ~1000 C for spodumene). By adjusting kiln speed, temperature, and additives, high conversion efficiency of lithium minerals is achieved.

4. Equipment Stability and Durability The shell is manufactured from high-quality steel and equipped with superior insulation and sealing structures, effectively reducing heat loss and extending equipment life. Its simple structure and reliable operation make it a highly mature calcination solution in the industry.

5. Intelligent and Automated Control Modern kilns generally integrate DCS control systems, wireless temperature monitoring, and remote intelligent variable-speed technology. This allows real-time monitoring of internal temperatures, flame status, and ring formation (accrual). Features include automatic ignition, flameout protection, fuel regulation, and remote operation, enhancing both efficiency and safety.

 6. Environmental Advantages The kiln tail gas has a relatively low temperature (280-350 C) and low dust content, facilitating downstream purification such as desulfurization, denitrification, and dust removal to meet strict environmental standards. In lithium battery recycling, pyrolysis rotary kilns can safely process spent batteries under anaerobic conditions to prevent hazardous emissions.

5.Technical Specifications

6.Our Solutions