Full-process Support for Metallurgical Silicon Smelting | Liming Heavy Industry’s Complete Range of Grinding Equipment Consolidates the Industrial Foundation

Metallurgical Silicon

Metallurgical silicon, also known as industrial silicon or crystalline silicon, is smelted from silica and carbonaceous reducing agents (including petroleum coke, cleaned coal, charcoal, etc.) in submerged arc furnaces. It contains approximately 98% silicon as the primary component.

It serves not only as a key supporting material for traditional industries, but also as a core raw material at the upstream supply chain for cutting-edge high-tech sectors including new energy, semiconductors and advanced new materials. Boasting four core properties- a high melting point, semiconductor characteristics, strong reducibility and alloy modification capability-metallurgical silicon is widely used in metallurgy, chemical engineering, machinery, electrical engineering, aerospace, shipbuilding, energy and other industries.

Driven by the rapid global growth of the new energy and semiconductor industries, market demand for metallurgical silicon continues to rise. However, the industry also faces major challenges including high energy consumption, excessive carbon emissions and increasingly stringent environmental regulations, which are accelerating its transformation toward green, low-carbon development and high-end production.

Liming Heavy Industry delivers a full integrated solution covering the entire industrial silicon production process: primary crushing, magnetic separation for impurity removal, high-efficiency grinding with LM vertical roller mills, cooling and finished product storage. We support the large-scale, intelligent, eco-friendly and high-efficiency utilization of silicon resources.

The core process of metallurgical silicon smelting is the carbothermal reduction method. The furnace feedstock requires silica with an SiO₂content of ≥99%, which is blended with carbonaceous reducing agents such as silicon coal, petroleum coke and charcoal. After precise batching and weighing, the raw materials are fed into a submerged arc furnace. Powered by graphite electrodes, the furnace temperature rises above 1800°C to trigger reduction reactions and produce liquid silicon. As key reducing agents, coal and petroleum coke directly affect the furnace reaction efficiency and the purity of finished silicon via their powder particle size and uniformity, making the pretreatment of these materials a critical upstream step for improving quality and reducing energy consumption in smelting.

The liquid silicon undergoes oxygen blowing refining, followed by ingot stripping and crushing, and is finally processed by grinding to produce finished products. Flue gas generated during smelting is captured by hoods and treated through flues, air coolers, fans, gravity dust removal and other processes to recover silica fume. Production wastewater is purified by activated carbon adsorption, enabling resource recovery while ensuring pollutant discharge complies with regulatory standards, in line with the industry’s green and low-carbon production requirements.

High-purity pulverization of metallurgical silicon is a vital link connecting smelting and high-end applications. Tailored and optimized for the hardness and purity requirements of industrial silicon, Liming Heavy Industry’s LM series vertical roller mills integrate drying, grinding, classification and conveying functions, providing a one-stop solution for silicon lump pulverization. They can produce custom silicon powder ranging from 30 mesh to 425 mesh to suit a wide variety of segmented application scenarios.

Smelting Raw Material Pretreatment

In metallurgical silicon smelting, grinding is the core process of raw material pretreatment. Carbonaceous reducing agents (bituminous coal, charcoal, petroleum coke, or only bituminous coal in the all-coal process) are finely ground by professional equipment and then shaped, followed by precise batching with silica. This creates high-quality furnace charge for high-efficiency smelting in submerged arc furnaces. Liming Heavy Industry’s full range of grinding equipment ensures a stable supply of raw materials.

Finished Metallurgical Silicon Pulverization

Finished metallurgical silicon is ground to 100–500 mesh for use in refractory materials, powder metallurgy, and silicone chemical production. Liming Heavy Industry’s LM vertical roller mills deliver high-efficiency fine pulverization, ensuring consistent particle size and stable product quality.

Graphite Electrode Production for Smelting Support

Graphite electrodes serve as the core conductive components of submerged arc furnaces in metallurgical silicon smelting. They are manufactured using calcined coke as the raw material, which undergoes fine grinding with specialized milling equipment before forming. This enables stable, efficient power transmission for submerged arc furnaces and ensures continuous smelting operations.

Wastewater Treatment

Coal-based activated carbon acts as the key purification material for metallurgical silicon smelting wastewater treatment. Produced by finely grinding coal powder with professional milling equipment, it is applied in activated carbon adsorption purification processes to effectively remove wastewater contaminants. This allows smelting wastewater to meet discharge standards and achieve recycling.

Core Advantages of LM Vertical Roller Mill

Developed to address the demanding processing requirements of metallurgical silicon and reducing agents- including high abrasiveness, flammability risks and strict high-purity specifications- Liming Heavy Industry’s LM series vertical roller mills adopt an innovative grinding mechanism for superior grinding efficiency. The fully negative-pressure enclosed operation effectively prevents dust leakage, while a five-stage explosion-proof protection system ensures safety during reducing agent pulverization and meets purity standards for high-grade silicon powder. A single machine fulfills the powder processing needs of the full range of upstream and downstream products across the industrial chain.

High Efficiency & Energy Saving, Low Operating Costs

The system integrates grinding, classification and enclosed conveying functions. Its compact structure allows outdoor installation and reduces civil engineering investment. The custom-designed grinding rollers and grinding table cut power consumption by 40%- 50% compared with Raymond mills, ball mills and other traditional milling equipment.

Intelligent Automatic Control, Stable & Safe Operation

Equipped with a fully automatic control system, it supports remote operation and safety interlock functions. A roller limiting device mitigates vibration, paired with an automatic slag removal function to discharge foreign materials promptly and ensure uninterrupted production.

Premium Finished Products, Higher Added Value

Materials remain inside the mill for a short dwell time. Particle size and composition can be precisely adjusted without over-grinding, and various impurities are automatically removed during production, complying with high-end industrial silicon material standards.

Five-Stage Explosion-Proof Safety Design

The system features five layers of explosion-proof safety measures, including online CO-O₂ monitoring and an automatic CO₂fire suppression system, delivering robust and reliable safety performance.

Easy Maintenance, Minimized Downtime Losses

The grinding rollers adopt thin oil lubrication and are fitted with a hydraulic roller lifting device. No full machine disassembly is required for maintenance, greatly reducing equipment downtime for servicing.

High-purity industrial silicon powder produced by Liming Heavy Industry’s LM vertical roller mill features precisely controlled particle size and consistently qualified purity. It has a wide range of applications and serves as a key basic raw material for silicone polymer materials, monocrystalline silicon, metallurgical casting, fine chemicals, refractory materials, aluminum-based alloys and other fields. It can broadly support high-end industries including new energy, chemical engineering, metallurgy, building materials, and electronic information.

As a total solution provider for grinding equipment, Liming Heavy Industry offers EPC general contracting services for powder production projects. We provide full-process guidance from preliminary project approval through to formal commissioning, to meet customers' integrated needs, enabling smoother project delivery and more efficient operation.

As a strategic raw material connecting traditional heavy industry and the green new energy sector, metallurgical silicon is witnessing a major industry shift toward low-carbon, safe and refined manufacturing. Centered on LM vertical roller mill, Liming Heavy Industry provides full-chain complete grinding equipment and EPC general contracting services for the entire metallurgical silicon production process, from raw material processing to finished products. With energy-saving, safe and intelligent grinding technology solutions, we deliver end-to-end support for industrial silicon smelting and continuously facilitate the green and low-carbon transformation and upgrading of China’s silicon industry.