Hot Metal Ladle Slag Remover: The "Slag-Iron Separation Expert" in Iron and Steel Production
In the production chain of modern iron and steel industry, hot metal pretreatment is a crucial link that determines the quality of subsequent steelmaking, and the hot metal ladle slag remover is an indispensable core equipment in this link. Like a "precision surgeon" on the iron and steel production line, it efficiently separates the molten slag from the hot metal through automated and mechanized operations. This not only improves the purity of hot metal but also ensures the stability and economy of the steelmaking process, making it an important equipment to promote the green and intelligent development of the iron and steel industry.
I. Core Function: Why Do We Need a Hot Metal Ladle Slag Remover?
After hot metal flows out of the blast furnace, it carries a large amount of molten slag formed by ore gangue, coke ash, flux, etc. If this molten slag is not removed in time, it will directly affect the efficiency of subsequent converter steelmaking and the quality of molten steel—not only increasing the consumption of slag-forming agents and prolonging the smelting time, but also possibly leading to excessive inclusions in the steel and reducing the mechanical properties of the steel.
The traditional manual slag removal method has problems such as high labor intensity, harsh working environment (high temperature, dust, harmful gases), low slag removal efficiency, and incomplete slag-iron separation, which cannot meet the large-scale and high-precision needs of modern iron and steel production.
The emergence of the hot metal ladle slag remover has completely changed this situation. It uses a robotic arm to drive a slag removal shovel or rake, performing precise operations in the hot metal ladle according to a preset trajectory. It efficiently scrapes off the molten slag floating on the surface of the hot metal and guides it into the slag pot, realizing the automated operation of "slag-iron separation". Data shows that after adopting mechanical slag removal, the efficiency of hot metal slag removal can be increased by more than 30%, the iron content in the slag can be reduced to less than 5%, while significantly reducing the amount of manual labor and the safety risks of high-temperature operations.
II. Working Principle and Core Structure: The "Solid Support" for Precise Operation
The working process of the hot metal ladle slag remover seems simple, but in fact, it integrates technologies from multiple fields such as mechanical design, hydraulic control, and automated programming. Its core logic is "precise positioning, stable operation, and efficient slag removal".
(I) Working Principle
Positioning and Alignment: After the hot metal ladle filled with hot metal is transported to the slag removal station by a crane or rail, the slag remover accurately determines the position, height of the hot metal ladle, and the liquid level height of the hot metal through a laser ranging or visual recognition system, ensuring that the slag removal shovel can accurately cut into the molten slag layer.
Slag Removal Operation: The hydraulic drive system drives the robotic arm to operate. The slag removal shovel is inserted into the molten slag at a certain angle (usually 5-10 cm deep into the molten slag layer to avoid iron loss caused by inserting into the hot metal layer). Then, the robotic arm moves along a preset trajectory (such as spiral or reciprocating), gradually scraping the molten slag to the slag outlet at the edge of the hot metal ladle, and the molten slag flows into the slag pot below through the slag outlet.
Operation Monitoring and Adjustment: During the slag removal process, operators can observe the slag separation situation in real-time through the monitoring screen. If there is excessive residual slag or hot metal being carried out, the speed, angle, or trajectory of the robotic arm can be manually adjusted to ensure the slag removal effect. After the operation is completed, the robotic arm resets and waits for the next hot metal ladle.
(II) Core Structure
The performance of the hot metal ladle slag remover relies on the coordinated work of four core structures, each of which needs to adapt to the harsh working conditions of high temperature and dust:
Robotic Arm System: As the "arm" of the slag remover, it usually adopts a multi-joint folding structure and is made of high-temperature-resistant alloy steel to ensure rigidity and stability in an environment above 1000°C. Some high-end models are also equipped with torque sensors, which can detect the slag removal resistance in real-time to avoid overload damage to the robotic arm.
Hydraulic Drive System: Responsible for providing power to the robotic arm, it uses a high-pressure hydraulic pump and explosion-proof hydraulic valve to ensure no leakage or failure in a dusty environment. The hydraulic oil needs to be equipped with a cooling and filtering system to prevent oil deterioration caused by high temperature and ensure driving efficiency.
Positioning and Control System: It has two modes: automatic and manual. In the automatic mode, precise control of the slag removal trajectory is achieved through the combination of PLC programming and sensors; in the manual mode, operators adjust the movement of the robotic arm through a joystick to cope with complex slag removal scenarios (such as slag agglomeration and fluctuations in the hot metal level).
Protection System: It includes a high-temperature-resistant protective cover for the robotic arm, a dust-proof sealing device for the equipment base, and a heat insulation and ventilation design for the operation room. Some models are also equipped with a spray cooling system to cool the robotic arm in real-time during slag removal operations, extending the service life of the equipment.
III. Technical Advantages
Compared with traditional manual slag removal, the hot metal ladle slag remover, with its mechanized and automated characteristics, shows significant technical advantages and has become a "standard equipment" in modern steel plants:
Improved Slag Removal Quality and Efficiency The trajectory accuracy of mechanical slag removal can be controlled within ±2 cm, which can evenly remove molten slag and avoid the problem of incomplete slag-iron separation caused by uneven force and angle during manual slag removal. At the same time, the continuity of mechanical operation can greatly shorten the slag removal time. Taking a 120-ton hot metal ladle as an example, manual slag removal takes 30-40 minutes, while mechanical slag removal only takes 15-20 minutes, with efficiency nearly doubled.
Reduced Costs and Losses On the one hand, mechanical slag removal can accurately control the insertion depth of the slag removal shovel, reducing the amount of hot metal carried out. The iron loss per ton of hot metal can be reduced by 0.5%-1%. Based on a steel plant's daily iron output of 10,000 tons, the annual iron loss can be reduced by 1,800-3,600 tons, directly saving costs by more than 10 million yuan. On the other hand, automated operations reduce manual positions, lowering labor costs and management costs, while avoiding safety accidents that may occur during manual high-temperature operations.
Improved Working Environment and Safety The remote monitoring and automated operation of the slag remover enable operators to avoid working in close proximity to high-temperature and dusty environments. In addition, safety devices such as overload protection and emergency stop of the equipment further improve operational safety, avoiding accidents such as molten slag splashing and tool scalding that may occur during manual slag removal.
Adaptation to Diversified Production Needs With the diversification of steel plant production capacity and hot metal ladle specifications, slag removers have also formed a series of products—from light slag removers suitable for small hot metal ladles below 50 tons to heavy slag removers suitable for large hot metal ladles above 300 tons, all of which can be customized according to customer needs. Some models also support multi-station switching, which can serve multiple hot metal ladle transfer rails at the same time, improving equipment utilization.
IV. Application Scenarios and Industry Trends: From "Basic Equipment" to "Intelligent Upgrade"
The hot metal ladle slag remover is widely used in iron and steel production links such as converter steelmaking, electric furnace steelmaking, and iron casting. Especially in large iron and steel complex enterprises, it has become the core equipment in the hot metal pretreatment section. For example, domestic large iron and steel groups such as Baowu Iron and Steel, Angang Steel, and Hebei Iron and Steel have all adopted hot metal ladle slag removers on a large scale, and some enterprises have even realized the linked automation of slag removal operations and hot metal ladle transfer, further improving production efficiency.
From the perspective of industry development trends, hot metal ladle slag removers will be upgraded towards "more intelligent, greener, and more efficient" in the future.
V. Conclusion
Although the hot metal ladle slag remover seems like a "niche equipment" on the iron and steel production line, it undertakes the important mission of improving molten steel quality, reducing production costs, and ensuring operational safety. As the iron and steel industry transforms towards intelligence and greenization, the hot metal ladle slag remover will continue to break through technical bottlenecks and become an "invisible contributor" to promoting the high-quality development of the iron and steel industry. For iron and steel enterprises, choosing a suitable hot metal ladle slag remover is not only an upgrade of production equipment but also a key step in enhancing core competitiveness.
Zhangjiakou Xuanhua Innovake Drilling Machine Co., Ltd. is a joint-stock enterprise specializing in the research and development, production, and sales of metallurgical machinery and equipment for ironmaking and steelmaking.
