Annual Output of 20,000 Tons of Calcined White Production Line Project (Shaanxi Yulin China)

I. Project overview

Date of signing: 2017-07-07

Processing material: Dolomite

Processing capacity: annual output of 20,000 tons

Equipment configuration: rotary kiln, vertical preheater, cooler, ball mill, dust collector, electrical instrument, etc

Shaanxi Yulin Fugu County annual output of 20,000 tons of calcined white production line project bidding in July 2017, our company was identified as the production line supply, installation supplier, in May 2018 commissioning, acceptance completed, equipment quality, safety recognized by the other side, production line energy saving, environmental protection, easy to operate.

Our company specializes in the production of metal magnesium smelting industry machinery and equipment, and according to the improvement of magnesium smelting process and the improvement of equipment level, constantly improve equipment performance, improve product functions, independent research and development and production of preheater successfully applied in dolomite calcination, waste gas heat recovery and utilization, fuel saving, increase production, but also conducive to the dust removal of flue gas, emission indicators to meet environmental standards.

This project mainly uses rotary kiln to complete the dolomite ore calcination according to the expected quality and production capacity, but compared with the previous magnesium calcined white production line, it pays more attention to energy consumption and environmental protection indicators.

II. Solution

The production line adopts the following main design scheme to solve the key problems of process, energy and environmental protection in the production of magnesium calcining white, and meet the requirements of customers.

1) According to the actual situation of the customer site planning process, reasonable equipment layout. As the customer site is square, the area is limited, not only rotary kiln, preheater, cooler and other large equipment and civil facilities, as well as workshop, warehouse, which requires the full use of land, reasonable planning layout. The project cooling machine, ball mill, kiln tail dust removal facilities, warehouse layout is compact and reasonable, not only to meet the production needs, but also to save land area.

2) Using vertical preheater with push head, energy saving and environmental protection. Vertical preheater with pusher head is a patented product of our company, which is used in conjunction with metal magnesium rotary kiln. Before the dolomite enters the kiln, the hot air from the kiln tail transfers heat through the material layer and is preheated to 800℃ to fully absorb heat. At the same time, reduce the exhaust gas temperature and dust concentration, avoid the subsequent bag dust collection filter bag high temperature damage, optimize the particle emission index.

3) Dolomite selection of energy-saving environmental protection rotary kiln. Magnesium metal rotary kiln is a special rotary kiln developed according to the calcining characteristics of dolomite and the process requirements of Pijiang process for magnesium refining. It is the key equipment of dolomite calcining system. The ratio of length to diameter of the rotary kiln is reduced from the traditional 20-25 to 20, which reduces the heat lost from the surface of the rotary kiln. Dolomite calcination temperature is 1250℃.

4) Use a single barrel cooling machine for material cooling. The high-temperature calcined white from the kiln is discharged into the cooling machine, and the heat is exchanged with the cold air and chain device in the cooling machine, the active calcined white is cooled below 100℃, and is sent to the calcined white bin, the air is preheated to more than 600℃, and the kiln is used to help the combustion.

5) Preparation of pulverized coal. The raw fuel of the system is pulverized coal, and the preparation of pulverized coal is made by an air-swept coal mill. The drying heat source is hot air drawn from the kiln head. The grinding material is equipped with a powder separator. The cold air baffle is installed on the hot air pipe of the kiln head, which can control the hot air temperature of inlet grinding according to the production needs.

6) Due to higher environmental protection requirements, dust collection ports are set up for each dust collection point, and reasonable arrangement of dust collectors to achieve partition management of dust collection points to meet environmental protection requirements; The tail gas is cooled by the preheater, filtered and purified by the bag dust collector, and discharged into the atmosphere by the chimney through the traction fan. The dust emission concentration is below 30mg/Nm3.

III. Project site