The core competitiveness of spinel bricks lies in their uniform and dense microstructure and stable physical and chemical properties. The density and uniformity of the green body are entirely dependent on precise control during the forming stage. The forming process must meet four key requirements: uniform density, dense structure, no cracks, and intact edges and corners. It is necessary to ensure uniform density throughout the green body, with a final volume density of 3.0-3.4g/cm³ and an apparent porosity of ≤13%, laying a solid foundation for subsequent high-temperature sintering. At the same time, it is essential to prevent the agglomeration of spinel particles and the stratification of raw materials during the pressing process to avoid defects such as loose structure, crack propagation, and spalling after sintering. Additionally, the pressing speed and holding time must be precisely controlled to accommodate the complex particle size distribution, poor air exhaust, and low fluidity of the spinel mixture, preventing the formation of internal pores in the green body that could lead to slag penetration and structural failure during high-temperature service. Moreover, the activity of magnesium-aluminum spinel particles must be protected to avoid oxidation and deterioration of the corrosion resistance of the product. Currently, the technical limitations of traditional forming equipment have led to widespread issues in spinel brick production, such as uneven density, green body cracking, edge and corner damage, large dimensional deviations, and low product qualification rates, severely restricting the industrial development of high-end spinel bricks. Zhengzhou Hualong, relying on its third-generation permanent magnet synchronous servo direct drive core technology, has optimized and upgraded the HLDS series of CNC servo screw presses, specifically addressing the pain points in spinel brick forming and creating dedicated forming equipment. With the core advantages of precise pressure control, flexible pressure transmission, and intelligent adaptability, it has established a benchmark for high-end spinel brick quality.

Compared to ordinary refractory bricks, the forming of spinel bricks is significantly more challenging due to the characteristics of the raw materials and performance requirements. The mixture is composed of coarse and fine spinel powders, high-purity magnesia sand, and alumina additives in precise proportions. The particle size distribution is wide, the fluidity is poor, and air exhaust is difficult. Moreover, magnesium-aluminum spinel particles are hard, brittle, and prone to oxidation, making it easy for particle agglomeration, micro-cracks in the green body, edge and corner damage, and surface oxidation to occur during the forming process. The requirements for the accuracy of the applied pressure, pressing speed, and holding time are extremely strict. It is necessary to achieve green body densification through precise pressing while ensuring uniform dispersion of spinel particles. At the same time, it is essential to avoid green body cracking and edge and corner damage caused by rigid impact, and to efficiently remove air from the mixture to prevent residual pores from affecting the product's thermal shock resistance and slag erosion resistance. Additionally, temperature fluctuations during the pressing process must be controlled to prevent oxidation and deterioration of spinel particles.

Zhengzhou Hualong has deeply studied the raw material characteristics, forming process logic, and industry upgrade demands of spinel 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. The equipment's precision, stability, and adaptability have been comprehensively upgraded, precisely matching the forming requirements of spinel bricks. It has become the preferred equipment for mass production of high-quality spinel bricks, assisting refractory material enterprises in creating high-quality products suitable for high-temperature, strong erosion, and strong thermal shock conditions.

Equipped with a core permanent magnet synchronous servo motor direct drive system, it has completely eliminated traditional low-efficiency transmission structures such as friction discs and clutches. The transmission chain is extremely short, with zero energy loss in energy transmission, and the pressure output is stable and controllable throughout the process. The equipment is equipped with Hualong's independently developed dedicated CNC pressure control module for spinel 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 complex particle size distribution, difficult exhaust, and easy agglomeration of spinel mixtures, a customized stepwise flexible pressurization process was developed. This process first applies light pressure to loosen the raw materials and slowly expel the residual air inside, then gradually and steadily pressurizes layer by layer, and finally maintains long-term pressure to shape the product. This ensures uniform force application to all parts of the green body, including the center, edges, and corners, and keeps the density fluctuation within a very small range. At the same time, it effectively prevents the agglomeration of spinel particles and the stratification of raw materials, protects the activity of spinel particles, and provides a solid foundation for the uniform combination of the bonding phase during subsequent high-temperature sintering. The qualified rate of finished products has been increased to over 99%.

The equipment adopts a fully enclosed static pressure screw, nut, and dedicated heavy-duty bearing transmission structure. During operation, a stable high-pressure oil film is formed for protection, achieving flexible and uniform pressure application and gradual pressurization. This completely avoids 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 green body and disperse the agglomeration of spinel particles, completely eliminating defects such as porosity, stratification, and micro-cracks, but also gently protect the activity of spinel particles, prevent the cracking and corner damage of the green body, 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.

Breaking through the structural limitation of the fixed lower dead point of traditional equipment, a stepwise forging forming mode is adopted. According to the material, size, structural complexity (metallurgical converter lining bricks, ladle bricks, special-shaped parts), and density requirements of spinel 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 types of spinel bricks, covering the full range of production scenarios for high-end refractory materials. There is no need to worry about the problems of uneven pressurization caused by deviations in raw material filling volume, differences in particle size distribution, and changes in the fluidity of the mixture. 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 requirements of high-end fields.

The equipment is equipped with a dedicated forming parameter database for spinel bricks, integrating the optimal forming process parameters for various specifications, different raw material ratios, and different density requirements of spinel bricks, including common products such as standard spinel bricks, special-shaped spinel bricks, and high-strength erosion-resistant spinel bricks. Operators can retrieve them with one click, eliminating the need for repeated debugging and exploration, and 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, porosity, and dimensional accuracy of each batch and each product are highly consistent, and the spinel particles are evenly distributed in the bonding phase, effectively avoiding particle oxidation, and easily meeting the strict quality requirements of high-end fields at home and abroad, helping enterprises smoothly open up the overseas high-end refractory materials market.

Compared with traditional friction presses, the Hualong servo screw press adopts an on-demand start-stop and sleep energy-saving intelligent mode. 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%. This significantly reduces the electricity cost of spinel brick production and meets the green and low-carbon development needs of the refractory materials industry. At the same time, the static pressure transmission structure has minimal wear, and is combined with a fully automatic forced lubrication system and an oil shortage alarm device, achieving maintenance-free operation, 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, and 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 precise feeding machines, closed-loop distribution machines, intelligent demolding machines, green body non-destructive testing equipment, and constant temperature conveyor lines, building an automatic and intelligent forming production line for spinel bricks. It realizes unmanned control throughout the process from distribution, pressing, pressure maintenance, demolding to green body transfer and inspection, minimizing human intervention. This not only avoids damage to the green body caused by manual operation but also ensures forming accuracy and production efficiency. It supports remote monitoring, parameter debugging, fault early warning, and production data traceability functions, facilitating domestic and foreign customers to manage production progress and product quality in real time from different locations. It fully conforms to the global refractory industry's trend of intelligent, digital, and green transformation, and helps enterprises build an intelligent production base for high-end spinel bricks.

Zhengzhou Hualong Machinery Co., Ltd. is a leading enterprise in the domestic electric servo screw press field. For 45 years, it has always focused on technological innovation in refractory forming equipment, delved into the pain points of the forming process of high-end refractories such as spinel bricks, and insisted on empowering the refractory industry upgrade with customized technology. The Hualong HLDS series of CNC servo screw presses cover the full tonnage range from 200T to 1600T. According to the customer's requirements for spinel brick material, specifications, production capacity, density, and raw material ratio, it can provide one-to-one customized forming solutions, fully meeting the mass production needs of various types of spinel bricks, and adapting to the supply of refractories in different high-end high-temperature, strong thermal shock, and strong erosion fields.