As we have known that nickle ore is devided into 2 kind of ore type that are Limonite and saprolite ore.Both of them can be treated to be made for Nicle Pig Iron with different content of nickle in ore for each type.According to the Nickle content of ore ,Saprolite type have high content of nickle than Limonite type, but both can be blended to accomplish nickle content desired.
After Mining of ore for futher action is to be smelting that will be done using either blast furnace or others machine to process ore to become NPI. There are several process which have to be passed to get NPI product ; Crushing, Drying , Sintering and ore smelting in the Furnace. Each stages needs energy / fuel to complete all phases .One of Fuel source to provide the energy is obtained from Gas recycling with all treatment processing before to be used as fuel.
Ore that is come from mining to stockyard have approximately diameter size between 20-30 cm it's passed ore screening stage in grizzly station before. Diametre more than 30 cm will be crushed to become smaller size of grains in the crushing machine and then to be sent at stockyard .
To achieve the required moisture of ore which it have to less than 25 % of moisture the materials needs to be dried through a rotary driyer machine.Where the heating action to the ores will decrease water content till the required moisture content is achieved.then the raw material will be sent to the Sintering machine by conveyor belt after passed the screening of ore.
All of fuel to dry the raw materil will be supplied from blast furnace off-gas processing chamber.
In this process the dried material that has passed several phase above will be homogenized of its size through by heating the material in the sintering machine moreover the sintering process will make the raw material to become ore with high viscousity and high porosity to overcome material stress when the material to be processed in blast furnace machine. Flux is normally limestone will be added and also coke or coke breeze as mixture before sintering to be done.To help the combustion in the sinter machine Gas from Blast furnace will be supplied from blast furnace after through several process in the blast furnace off-gass chamber.
4.Blast furnace / smelting process
The last processing to get NPI is smelting sintered ore in the blast furnace machine . the sintered ore together with coke being feed in the bast furnace through the top of blast furnace. Since the gravitation force influence then the material will be slowly descending along bast furnace chamber ( Shaft,Belly , bosh and Heart part ).
When the feeding material is started heat from bottom of blast furnace ( tuyeres ) is occurred and will change coke into carbon monoksida as fuel to melt the sintered ore into molten and slag through some stage liquefaction. The heat needed to this process until 1800C resulted by combustion coke is started by Air gas injection from tuyeres that all of gas come from Hot stove through refractory pipe installation and the gas that processed in the Hot stove is supllied by leaved gas from top of Blast furnace.