一步法回转窑生产还原铁热压块项目
One-step Rotary Kiln Producing Reducing Iron Hot-pressing Block Project
一、 工艺简介
Introduction of the Process
1. 还原铁热压块(HBI)生产工艺
Production Process of Reduced Iron Hot-pressing Block (HBI)
用天然气或煤气做热源的回转窑还原技术 热压成型钝化机压块是我公司 新研发生产还原铁热压块新工艺技术，新工艺节能环保，已经申报国家发明 zhuan li。我公司研发的回转窑 热压成型钝化工艺，与传统工艺有了很大改进，用天然气或煤气做热源，用CO气体和无烟煤做还原剂，不但回转窑操作变得简单，回转窑结圈几率降低，运行更可靠，同时由于增加了热压成型钝化系统， 大限度防止了再氧化和利用了余热，降低了能耗和生产成本。
Rotary kiln reduction technology with natural gas or gas as heat source and passivator pressing block by hot pressing are the latest research and development of new technology for producing reduction iron hot pressing block by our company. The new technology is energy-saving and environmental protection, and has declared the national invention patent. It not only makes rotary kiln operation easy, Rotation kiln ringing rate becomes lower and the operation is more reliable. At the same time, due to the addition of passivation system for hot pressing forming, the waste heat is maximally utilized, and the energy consumption and production cost are reduced.
该工艺主要针对铁矿粉或氧化铁皮进行还原，所用原料有铁矿粉（氧化铁皮）、还原剂（CO 无烟煤）及脱硫剂。主要设备包括配料压球系统、烘干加热系统、二次燃烧室系统、回转窑还原系统、热压成型钝化系统、尾气抽风净化系统、喷煤系统和循环水冷却系统等。
The process is mainly aimed at reducing iron ore powder or oxide scale. The raw materials used are iron ore powder (oxide scale), reducing agent (CO anthracite) and desulfurizer. The main equipments include batching and ball-pressing system, drying heating system, secondary combustion chamber system, rotary kiln reduction system, hot pressing passivation system, exhaust air purification system, coal injection system and circulating water cooling system etc.
主要工艺流程是铁粉、氧化铁皮、粘结剂按一定比例混合后，通过皮带机输送到强制混料机中，经过强制搅拌混合的料通过皮带机进入储料仓中，储料仓4个，下面安装有圆盘给料机，可根据压球机产量调节圆盘给料机给料量，铁粉料通过皮带机加到压球机中，压球机压好的球，通过皮带机进入链板式烘干机中。铁粉球在链板式烘干机中被来自烧结回转窑的热风烘干加热，二次燃烧室排出的高温尾气直接进入烧结回转窑，烧结回转窑烧结的球团,温度高达11０0℃，密闭送进还原回转窑中进行加热还原，经回转窑还原的高温还原球团在窑头出料口进行筛分，筛下物加湿降温后有螺旋上料机排出，费焦经处理后，颗粒料可以继续使用。筛上的热还原球团经压块机进行热压钝化处理， 终出还原铁热压块（HBI）产品。
The main process is that after mixing iron powder, iron oxide scale and binder in a certain proportion, the material is conveyed to the forced mixer through belt conveyor. After forced mixing, the material is entered into the storage bin through belt conveyor. There are four storage silos with disc feeders installed below. The feeding quantity of disc feeder can be adjusted according to the output of ball press. Iron powder is added to the ball press through belt conveyor. The ball pressed by the machine enters the chain plate dryer through the belt conveyor. Iron powder pellets are heated by hot air drying from sintering rotary kiln in chain plate dryer. The high temperature tail gas from secondary combustion chamber enters sintering rotary kiln directly. The sintered pellets in sintering rotary kiln are fed to reduction rotary kiln at a temperature as high as 1100 C. The high temperature reduction pellets reduced by rotary kiln are screened at the outlet of kiln head, and the sieve material is humidified and cooled. The screw feeder discharges the coke, after treatment, the granular material can continue to use. The hot reduction pellets on the sieve were passivated by hot pressing with a compactor, and the reduced iron hot pressing block (HBI) product was finally produced.
2、设备工艺布置图
Equipment Process Layout
3、天然气回转窑还原技术 热压成型钝化工艺主要特点
The Features of Reduction Technology Hot Pressing Passivation Technology for Natural Gas Rotary Kiln
用天然气或煤气做热源的回转窑还原技术，再配加二次燃烧室 成品筛分热压块以后，生产工艺与传统的回转窑艺有了很大的区别。
Reduction technology of rotary kiln using natural gas or gas as heat source and adding secondary combustion chamber finished product sieving hot pressing block, the production process is quite different from the traditional rotary kiln process.
1）、回转窑长度变短，一般在40m-60m左右,使投资减少；同时由于回转窑变短，回转窑热平衡极易建立，操作变得简单。由于物料在窑内时间变短，同时由于还原采用无烟煤颗粒，强度好，摩擦产生的粉末减少，使窑炉炉衬结圈几率降低 ，设备运行更可靠；
1). The length of the rotary kiln becomes shorter, generally about 40m-60m, so that the investment is reduced; at the same time, as the rotary kiln becomes shorter, the heat balance of the rotary kiln can be easily established and the operation becomes easier. As the material in the kiln becomes shorter, at the same time, anthracite particles are used for reduction., the iron powder produced by the friction is reduced, so that the kiln furnace liner lining is less likely to be ringed, and the equipment operation is more reliable.
2）、特殊的加热燃烧和喷煤方式及回转窑二次风机，使回转窑内温度均匀，还原区温度基本在1100℃～1150℃；
The special coal injection method and secondary fan of rotary kiln make the temperature of the short rotary kiln uniform and the kiln tail temperature reaching 1100 ~ 1150 degrees;
3）、由于尾气中富含煤气，设立二次燃烧室可以燃烧掉尾气中的CO等可燃成分，不仅可以使尾风温度提高到1150℃，而且利用尾风也可保证安全可靠；
Because the exhaust gas is rich in gas, setting up a secondary combustion chamber can burn off the combustible components such as CO in the exhaust gas, which can not only raise the temperature of the exhaust to 1150 C, but also ensure the safety and reliability of the exhaust.
4）、回转窑排出的混合还原料，经特制高温震动筛处理后，纯净高温还原球团直接进入热料压机热压钝化处理，热压块密度可达6.5-6.8t/m³；
the mixed reducing material discharged from rotary kiln is treated by special high temperature shaking screen. The pure high temperature reducing pellet is directly passivated by hot pressing machine. The density of hot pressing pellet can reach 6.5-6.8t/m.
5）、对筛分出的废焦进行处理，大于2mm颗粒可以继续使用，减少了还原剂使用量，降低生产成本；
The sifted waste coke can be treated, and particles larger than 2mm can be used continuously, which reduces the amount of reductant used and reduces the production cost.
6）、用天然气或煤气作为热源，CO 煤炭颗粒还原，尾气含尘量大大降低，经除尘器处理后完全可以达到规定的尾气排放标准。
Natural gas or gas is used as heat source and CO coal particles are reduced, the dust content of tail gas is greatly reduced, and the tail gas can completely meet the prescribed emission standard after being treated by dust collector.
7）、二次燃烧室将尾气中可燃成分燃烧后排出的高温尾气首先进入烧结回转窑对球团加热烧结，然后再进入链板式加热器对冷球团进行烘干， 大限度利用热能，提高能源利用率，降低成本。
The high-temperature exhaust gas from the combustible components in the tail gas of the secondary combustion chamber first enters the sintering rotary kiln to heat and sinter the pellets, and then enters the chain-plate heater to dry the cold pellets, so as to maximize the use of heat energy, improve the utilization rate of energy and reduce costs.
4.原材料工艺要求
The requirement of the raw material
1） 铁粉（铁矿石）
Iron powder
铁粉TFe≥68%，粒度＞80目
Iron powder TFe≥68%, particle size>80 mesh
2）还原剂
Reducing agent
本项目还原剂为无烟煤，每吨球团需要450Kg，无烟煤粒度为10mm-20mm.
The reducing agent of this project is anthracite. Each ton of pellets needs to 450 Kg. Anthracite particle size is 10 mm-20 mm.
3）石灰石
Limestone
CaO含量＞55%，粒度小于5mm
CaO content > 55%, particle size less than 5 mm
4)天然气
Natural gas
天然气热值＞8000大卡
Calorific value of natural gas > 8000 calories
5.产品要求
1）、金属化率
产品平均金属化率90%-92%，含碳量0.5-1%
3）产品形状
产品为直接还原铁热压块（MBI），还原铁块外形为直径200-220mm,高度150-200mm的圆柱体，密度6.5-6.8t/m³。