rotary kiln for nickel
Laterite nickel rotary kiln
Application: building materials, chemical, metallurgy, and other industries.
Nickel rotary kiln is the key equipment used in the laterite nickel production line. Laterite nickel rotary kiln is used for nickel-iron reduction. The main raw material is laterite nickel ore. The reducing agent can be cheap coal, peat coal, or medium coal.
About laterite nickel
The main minerals of nickel ore include pyrrhotite, serpentine nickel ore, garnierite or nickeliferous pyrite, and red nickel ore. Nickel-iron is used as an alloying element additive in the steel industry to improve the bending strength and hardness of steel. Nickel can make the structure of cast iron uniform and increase its density. It can also be used as an additive for nickel or nickel-chromium cast iron rolls and other casting alloys. Nickel-iron is a high-iron metal compound with a high comprehensive utilization value and is widely used in various industries such as industry, construction, chemical, and metallurgy. It plays a very important role.
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Processing of nickel rotary kiln
The investment costs and operational difficulties vary for different nickel ore processing techniques. The impact of rotary kilns on the overall energy consumption and product quality in the nickel-iron smelting process also varies. Therefore, as nickel-iron production scales up, it is worth analyzing which nickel ore pretreatment method to choose.
1. Firstly, we introduce the processing of a normal rotary kiln for nickel calcination. This type of processing has some advantages compared to RKEF Nickel process, such as: less fuel cost, because it use cheap coal, not coke or electricity; more selection of raw materials; finished nickel ferro (containing about 20% Ni) can be directly used as raw material for stainless steel production; It can be used as coolant in molten steel smelting.
- The working zone of a rotary kiln for nickel ore can be divided into three sections: drying section, heating section, and roasting section.
- In the rotary kiln, the nickel ore is calcined and dehydrated, resulting in a weight reduction of approximately 30%.
- At the same time, nickel oxide and some iron are reduced by the reducing agent in the furnace charge.
- A sealed discharge device is located at the discharge end of the rotary kiln, and the nickel slag is discharged at a temperature of 600-900°C, while being insulated, and then sent to the insulated feeding bin of the ore hot furnace for insulation. It is then uniformly distributed into the ore hot furnace through a sealed pipe-like feeding device.
- The ratio of diameter to length of the rotary kiln varies depending on the treatment method of the furnace charge.
- The burner structure of the rotary kiln is important for effectively adjusting the length and stiffness of the flame to ensure that the temperature in the three working zones of the kiln is within the required range.
- Additionally, the utilization of the rotary kiln’s flue gas for drying the raw materials should be fully considered for energy conservation.
2. Secondly, RKEF Nickel is another hot processing on the market we can’t ignore. The RKEF process for nickel can be generally divided into these steps: Ore blending – Rotary kiln drying – Rotary kiln roasting – Electric furnace smelting of crude nickel-iron – LF furnace refining (or mechanical stirring desulfurization) – Water quenching of refined nickel-iron – Production of qualified nickel-iron granules.
- The RKEF process is mature, highly efficient in production, and has a relatively high nickel recovery rate (about 95%).
- It is easy to achieve automated control, can achieve higher smelting temperatures, and can handle refractory materials.
- Due to the high process smelting temperature (around 1500°C), a large amount of coke and electrical energy are required, resulting in high comprehensive energy consumption.
- The nickel grade of the ore has a significant impact on production costs, with approximately a 3-4% cost increase for every 0.1% decrease in nickel grade.
- From an economic perspective, it is suitable for processing medium to high-grade laterite nickel ores (with a nickel content greater than 2% and cobalt content less than 0.05%), and it requires high-quality coal and abundant local power or fuel supply.
parts of nickel rotary kiln
Kiln shell and kiln lining: The kiln shell is made of rolled steel plates. The temperature inside the kiln can reach above 1450°C, so the kilns shell is lined with refractory bricks to protect the shell and reduce heat loss..
Heat exchanger: To enhance heat transfer efficiency, various types of chains are often suspended inside the kiln shell to form a heat exchange device.
Kiln tyre: The weight of the kiln shell, kiln lining, and materials in the rotary kiln is transmitted to the supporting device through the kiln tyre.
Supporting device: It consists of a pair of trunnion bearings and a large base. The trunnion supports a riding ring, allowing the cylinder to rotate freely while transferring a significant load to the foundation. The supporting device typically has 2-7 gears, and one or several gears are equipped with kiln thrust roller, known as gear retaining supporting devices. Their function is to restrict or control the axial movement of the rotating part of the kiln.
Drive device: A gear ring is installed in the middle of the cylinder, secured by spring plates. The rotation of the cylinder is achieved through gear transmission. Additionally, to facilitate operation and maintenance, large rotary kilns are equipped with auxiliary drives that allow the kiln to rotate at extremely low speeds.
Kiln hood: It serves as an intermediate connection between the kiln head end and the downstream equipment in the process. It is the area where operators conduct production operations and is equipped with observation holes and inspection doors.
Burner: The burner of the rotary kiln is mostly inserted from the kiln head end and radiates flames to heat the materials to the required temperature. The burner can have coal injection pipes, oil sprayers, gas nozzles, etc.
Cooler: It serves as an intermediate connection between the kiln tail and the material feeding device as well as the gas treatment equipment. The exhaust gas is discharged through the cooler and enters the flue and dust collection system. The materials are fed directly into the tail of the kiln by the feeding device.
Feeding device: It is an auxiliary equipment of the rotary kiln. The feeding requirements are stability, uniformity, and ease of control to match the kiln operation.
why choose us?
The nickel rotary kiln process is simple and require less maintenance, lower investment and short pay-off period;
less production cost
The fuel of rotary kiln for nickel calcination is coal, using this technology to smelt 1 ton of nickel-iron only needs 4.5 tons of standard coal, and electricity consumption is less than 40%, which can greatly reduce the cost of production;
wide range of raw materials
Raw materials can be selected freely, the Laterite-nickel ore from Southeast Asia is better choice, the finished product- nickel-iron can be used as the raw material of stainless steel production;