Beijing Liulihe Cement Co., Ltd. owns an integrated cement grinding system with an annual capacity of 1 million tons. The original two mechanical mixers suffered from persistent dust leakage, frequent breakdowns, heavy maintenance workload and high power consumption, which restricted continuous production. The company replaced the old mixers with FH800*4000-2 pneumatic-mechanical composite mixers manufactured by Longzhou Machinery. This twin-shaft composite mixer has a total installed power of only 18.5 kW. After commissioning, the equipment uptime exceeds 95%, with zero material leakage and mixing uniformity deviation kept within ±2%, guaranteeing stable cement quality. The two composite mixers can save 1,317,600 kW·h of electricity per year, equivalent to 430.86 tons of standard coal, reducing CO₂ emission by 1,128.85 tons as well as SO₂ and NOₓ emissions. The investment for one mixer can be recovered within four months merely through electricity savings. Nearly one year of on-site operation proves that this equipment combines pneumatic and mechanical mixing merits, featuring advanced mixing principle, remarkable energy saving and easy maintenance, reaching internationally advanced level. It can be widely promoted in new cement lines and cement grinding plants to achieve cost reduction and carbon emission reduction.

Separate grinding in cement final production mixes clinker powder and supplementary materials. This article introduces mechanical & pneumatic-mechanical composite mixers, presents a practical case of FH800-2 mixer application, and analyzes mixing performance, energy saving and capacity improvement.

The enlargement and complication of cement grinding systems and higher clinker feeding temperatures lead to excessively high finished cement temperatures, which cause false setting, degrade concrete quality, and damage conveying and packaging facilities. Effective cement cooling is therefore crucial for stable production. This article presents the working principle, key features, applicable material criteria and selection instructions of a cement cooler. The equipment adopts internal cooling water tanks and full cement aeration to enhance heat exchange efficiency, enabling horizontal feeding and discharging with a simplified process layout. Equipped with a closed-loop water circulation system, the cooler achieves low energy consumption (≤0.5 kW/t) and can provide a temperature drop of over 30 °C when material temperature exceeds 95 °C and water temperature is below 30 °C. The applicable materials are non-viscous powder with moisture content below 1.5% and bulk density less than 2 × 10³ kg/m³. Proper model selection, layout design and supporting cooling water system, together with negative-pressure operation, are required to ensure reliable cooling performance in practical application.