Precision pressure control for casting high-quality products: Empowering the upgrade of magnesia-chrome bricks - Servo screw press sets a new benchmark for refractory material forming

Magnesia-chrome bricks are made from high-purity fused magnesia sand and chromite (or chromium oxide) as the main raw materials, combined with magnesia fine powder, chrome powder and other auxiliary materials, and special high-temperature binders. The forming process must take into account "high density, high compactness, uniform composition and structural integrity" - ensuring uniform density throughout the body, ensuring the finished product's compressive strength meets standards, with reasonable pore distribution and small pore size, while avoiding the breakage of magnesia-chrome particles and micro-cracks in the body during the pressing process, and preventing the separation of magnesia and chromite particles and composition segregation, to ensure the product's resistance to slag erosion, thermal shock and spalling at high temperatures. Currently, the technical shortcomings of traditional forming equipment have led to common problems in magnesia-chrome brick production, such as uneven density, body cracking, composition segregation, low product qualification rate, and unstable batch quality, seriously restricting the industrialization of high-end magnesia-chrome bricks. Zhengzhou Haloong, relying on the third-generation permanent magnet synchronous servo direct drive core technology, has upgraded the HLDS series of CNC servo screw presses, specifically addressing the pain points of magnesia-chrome brick forming, creating dedicated forming equipment. With the core advantages of precise pressure control, flexible pressure transmission, and intelligent adaptation, it has established a new benchmark for high-end magnesia-chrome brick quality.

Compared to ordinary refractory bricks, the forming of magnesia-chrome bricks is significantly more difficult. The magnesia sand particles in the raw materials are hard and angular, while the chromite particles are dense and unevenly distributed. The mixed material has poor fluidity, a large particle size range, and is prone to layering and segregation. The requirements for the accuracy of the applied pressure, the pressing speed, and the holding time are extremely high - it is necessary to achieve densification of the body through precise pressing, ensuring that the finished product's compressive strength is ≥75MPa and the volume density is controlled between 2.8-3.1g/cm³, while avoiding the breakage of magnesia-chrome particles and the generation of micro-cracks in the body due to rigid impact. At the same time, it is necessary to precisely control the pore distribution to prevent the separation and segregation of magnesia and chromite, ensuring the product's resistance to slag erosion and thermal shock.

Zhengzhou Haloong has deeply studied the raw material characteristics, forming process logic, and industry upgrade demands of magnesia-chrome bricks. With the core technology of permanent magnet synchronous servo motor direct drive + static pressure flexible pressure transmission + intelligent CNC system, it has specifically optimized the HLDS series of servo screw presses, comprehensively upgrading the equipment's precision, stability, and adaptability, precisely matching the forming requirements of magnesia-chrome bricks. It has become the preferred equipment for mass production of high-quality magnesia-chrome bricks, assisting refractory material enterprises in creating high-quality products suitable for high-temperature applications.

Equipped with a core permanent magnet synchronous servo motor direct drive system, it has completely eliminated the inefficient transmission structures such as traditional friction discs and clutches, with an extremely short transmission chain and zero energy loss in energy transmission. The pressure output is stable and controllable throughout the process. The equipment is equipped with Haloong's self-developed dedicated CNC pressure control module for magnesia-chrome bricks, which can digitally and precisely set the impact energy, pressing speed, stepwise pressing times, and holding time. The energy repetition control accuracy is ≤±1%, ensuring that the pressure in each forming process is highly consistent, completely eliminating quality deviations caused by manual operation and mechanical fluctuations. In response to the characteristics of poor fluidity, easy layering and segregation, and hard particles of magnesia-chrome mixed materials, a customized stepwise flexible pressing process has been developed. It first applies light pressure to disperse the raw material agglomerates and quickly expel the residual air inside the body, then applies stepwise stable pressure to compact the body layer by layer, and finally maintains long-term pressure for shaping. This ensures uniform force application throughout the body, including the center, edges, and corners, with density fluctuations controlled within a very small range. At the same time, it effectively suppresses the layering and segregation of magnesia and chromite, ensuring uniform composition. It not only ensures the body's compactness but also avoids the breakage of magnesia-chrome particles, perfectly balancing the core advantages of high strength, slag resistance, and thermal shock resistance of the product, with the product qualification rate increasing to over 99%. The equipment adopts a fully enclosed static pressure screw, nut and special heavy-duty bearing transmission structure. During operation, a stable high-pressure oil film is formed for protection, achieving flexible and uniform force application and pressure relief, completely avoiding the severe impact force and stress concentration problems brought by traditional rigid pressurization. The pressurization process is smooth and gentle, with uniform and soft pressure transmission. It can not only fully expel the internal pores of the blank, disperse the agglomerated raw materials, and completely eliminate defects such as porosity, delamination, and cracks, but also gently protect the structure of magnesia-chrome particles, prevent particle breakage and blank cracking, significantly reduce the waste of high-cost raw materials, and effectively extend the service life of the mold, reduce material costs, and improve the production efficiency of the enterprise.

It breaks through the structural limitation of the fixed bottom dead center of traditional equipment and adopts a step-by-step forging forming mode. According to the material, size, structural complexity (standard brick, special-shaped brick), density and magnesia-chrome content requirements of magnesia-chrome bricks, the stroke of the slider, the pressurization depth and the applied pressure can be flexibly adjusted to precisely match the forming requirements of various magnesia-chrome bricks, covering the full range of production scenarios for high-end refractory materials. There is no need to worry about the deviation of raw material filling volume, the difference in magnesia-chrome particle size, and the layering of the mixed material causing uneven pressurization. Combined with a rapid mold changing system, mold changing is convenient and efficient, perfectly adapting to the flexible mode of multi-variety and batch production, meeting the batch supply needs of the high-end field.

The equipment is equipped with a dedicated forming parameter database for magnesia-chrome bricks, integrating the optimal forming process parameters for various specifications, different magnesia-chrome content, and different density requirements of magnesia-chrome bricks, covering the forming parameters of common products such as ordinary dense type, high-strength slag-resistant type, and special-shaped magnesia-chrome bricks. Operators can retrieve them with one click, eliminating the need for repeated debugging and exploration, significantly reducing the interference of human factors on product quality. All forming parameters can be permanently saved and reused in batches, ensuring that the density, compactness, composition uniformity, and dimensional accuracy of each batch and each product are highly consistent, easily meeting the strict quality requirements of the high-end field at home and abroad, and helping enterprises smoothly open up the overseas high-end refractory materials market.

Compared with traditional friction presses, the Haloong servo screw press adopts an intelligent mode of on-demand start-stop and sleep energy saving. The servo motor only operates during the pressing process, and the standby state is completely zero energy consumption, with a comprehensive energy-saving rate of over 55%, significantly reducing the electricity cost of magnesia-chrome brick production, meeting the green and low-carbon development needs of the refractory materials industry. At the same time, the static pressure transmission structure has minimal wear, combined with a fully automatic forced lubrication system and an oil shortage alarm device, achieving maintenance-free operation, with a low equipment failure rate and a service life far exceeding that of traditional equipment. The later maintenance cost is reduced by more than 40%, comprehensively compressing production, maintenance, and material costs, helping enterprises achieve a green, low-carbon, and efficient profit-making production model.

The equipment is equipped with standardized industrial communication interfaces, which can be seamlessly linked with automatic and precise feeding machines, closed-loop distribution machines, intelligent demolding machines, non-destructive testing equipment for blanks, and constant-temperature conveying lines, building an automatic and intelligent forming production line for magnesia-chrome bricks, achieving unmanned control throughout the process from distribution, pressing, pressure holding, demolding to blank transfer and testing, minimizing human intervention. It not only avoids damage to the blank caused by manual operation but also ensures forming accuracy and production efficiency. At the same time, it supports remote monitoring, parameter adjustment, fault warning, and production data traceability functions, facilitating domestic and foreign customers to remotely and real-time control production progress and product quality, fully in line with the global refractory materials industry's trend of intelligence, digitalization, and green transformation, helping enterprises build an intelligent production base for high-end magnesia-chrome bricks.

As a leading enterprise in the domestic electric servo screw press field, Zhengzhou Haloong Machinery Co., Ltd. has been focusing on the technological innovation of refractory material forming equipment for 45 years, deeply exploring the forming process pain points of magnesia-chrome bricks and other high-end refractory materials, and insisting on empowering the refractory materials industry with customized technology. The Haloong HLDS series of CNC servo screw presses cover the full tonnage range from 200T to 1600T. According to the customer's requirements for magnesia-chrome brick material, specifications, production capacity, density and magnesia-chrome content, we can provide one-to-one customized forming solutions, fully meeting the mass production needs of various magnesia-chrome bricks and adapting to the supply of refractory materials in different high-end high-temperature fields.