Active Calcium Oxide Production Line with Annual Output of 200,000 Tons (Xiaoyi, Shanxi, China)

I. Project overview

Signing Date: 2018-04-17

Handling material: Limestone

Processing capacity: 200,000 tons per year

Equipment configuration: vertical preheater, 4*60m rotary kiln, vertical cooler, air sweep coal mill and other main equipment.

The first phase of the project is built by our company with an annual output of 200,000 tons of active calcium oxide. The project adopts the continuous closed production process of the United States and Italy, which greatly improves the use efficiency of raw materials. It not only reduces energy consumption, reduces soot emissions, but also reduces the production cost of enterprises, so as to meet the production requirements of energy saving and environmental protection activity. It has brought economic benefits to enterprises and also adapted to the needs of the market, which is in line with the business philosophy of developing circular economy.

II. Solution

(1) Raw material storage and transportation

The limestone with particle size of 10 ~ 50mm is transported to the factory and stacked in the material yard, and the material yard is operated by loaders. The material with qualified particle size is loaded into the receiving trough set up in the material yard by the loader, the receiving trough is fed quantitatively by the feeder, the stone is fed to the high Angle conveyor, and then sent to the screening building. After the qualified particle size of the limestone is screened, it is weighed by the high Angle conveyor and sent to the top silo of the preheater. The powder under the screen is sent to the storage yard by the conveyor and is carried out by the forklift regularly.

(2) Calcination of limestone

Limestone calcining is composed of vertical preheater + rotary kiln + vertical cooler, the output is 100~800t/d, the material from the top of the preheater bin through the feed chute into the preheater body, while the high temperature flue gas from the rotary kiln preheats the material to more than 1000℃, causing partial decomposition of limestone, and then pushed into the tail of the rotary kiln by hydraulic push rod in turn. After high temperature calcination in rotary kiln, it is discharged into the cooler, cooled by the cold air blown into the fan, and cooled to the ambient temperature of +60℃ below the cooler. The air blown in by the cooler enters the rotary kiln as secondary air to participate in combustion.

(3) Finished product transportation

After the finished lime is discharged from the cooler, it is transported to each finished lime warehouse by chain conveyor, bucket elevator and belt conveyor. The discharge valve under the lime storage bin is used to load the lime in the bin into the car and the tank car before being transported out. Set up different size silos according to customer reserve requirements.

The finished product silo adopts circular silo, with 2 finished products silos of 5~50mm and 1 finished product silo of <5mm. The quantity of each silo is about 800t.

(4) Flue gas treatment

After heat exchange with limestone in the preheater, the temperature of the high temperature flue gas produced by the combustion of rotary kiln is reduced to below 250℃, and then the cyclone dust collector is carried out for the first stage of dust collection, the large particles of dust are captured, and then into the bag dust collector. After dust removal, the high temperature fan is discharged into the atmosphere, and the dust concentration of the discharged gas is less than 30mg/m3. A cold risk control system is installed at the inlet of the dust collector to protect the dust collector.

III. Project site