CN1070237C - Process for making acidic spheroidized ore - Google Patents

Abstract

The present invention relates to a process for making an acidic spheroidized ore. In the present invention, a high-grade iron ore concentrate is used as a raw material, bentonite is used as a binding agent, a coal powder instead of gas or liquid fuel is adopted for the combustion of material layers, a consolidatation mechanism for acidic spheroidized ores is adopted, and a sintering machine is adopted to produce the acidic spheroidized ore; the present invention has the advantages that the present invention improves the structures of blast furnace charges, and saves investment by 85% or so; in addition, the present invention has the advantages of high output and low energy consumption, the utilization coefficient of the sintering machine is 1.5 to 1.7 t/m<2>. h, the solid energy consumption is 50 Kg/t. p, and the fuel consumption is 50 Kg/t. P; the spheroidized ore has the advantages of high iron grade (TFe is more than 60%), high intensity (ISO drum strength is more than or equal to 70%), good reducibility (RI is more than 55%) and low reduction degradation index at a low temperature (RDI<+3.15> is more than or equal to 75%).

Description

A kind of process for making acidic spheroidized ore

The present invention relates to a kind of manufacture method of blast furnace ironmaking raw material.

Conventional both at home and abroad at present blast furnace ironmaking raw material can be divided into acidic pellet ore and agglomerate, the acidic pellet ore production method can be divided into shaft furnace pelletizing method, the belt machine roasting method, chain grate machine---kiln process three major types, usually provide pellet roasting required thermal source with geseous fuel or liquid fuel combustion, domestic also have a part producing producer coal dust firing that uses solid fuel, be used for shaft furnace pellet roasting method, but the burning of coal dust is carried out outside stove, the consolidation mechanism of above-mentioned several method is the solid phase diffusion bonding, having material requires high, investment is big, the shortcoming of easy ring formation in the production cost height, kiln.Chinese patent application (application number 98102028) proposes a kind of method of producing acid pelletizing sinter with sinter machine, its consolidation mechanism is to lean on calcium ferrite liquid phase (high basicity) or fayalite liquid phase and the glassiness (acid burden material) to be bonded to agglomerate, but the agglomerate reductibility that is generated is poor, intensity difference, grade is low, is unfavorable for the reinforcing blast furnace smelting.

In order to solve above deficiency, the invention provides a kind of method of utilizing the acidic pellet ore consolidation mechanism, adopting sinter machine production acidic pellet ore.

The present invention is with high grade iron concentrate (TFe63～66%, SiO ₂＜5.5%) is raw material, adds wilkinite and make binding agent, adopt coal dust directly to allocate bed of material burning into, utilize the acidic pellet ore consolidation mechanism, adopt sinter machine to produce acidic pellet ore, comprise batching, make ball, processes such as drying, igniting, roasting, fragmentation, screening, specific embodiment is as follows:

A＞use wilkinite is made binding agent, strengthen and make ball and pellet roasting, wilkinite proportioning 1.0～2.0% (weight percents, as follows), coal dust place of gas fuel or liquid fuel use solid fuel, the coal dust proportioning is that (granularity＜3mm), interior coal blending powder proportioning is 1.2～1.5% to 3.5～4.5% (weight percents) when wherein making ball.

Outer coal blending powder proportioning is 2.3～3.0% behind b＞the make ball, and to reduce production costs, employing garden dish pelletizer is made ball, then in the tube mixing machine of garden with coal dust and pelletizing mixing, to control coal dust firing speed in the bed of material.

C＞green-ball granularity control 5～15mm 〉=80%, green-ball moisture 7.5～10%, compression strength of green pellet 〉=10 N/, shatter strength of green pellet 〉=4.5 time/0.5 meter.

D＞bed depth is 500～700mm, before the igniting roasting dryer section is set, and accounts for 5～20% of roasting time time of drying, and 200～300 ℃ of drying temperatures are thermal source with pellet cooling exhaust or lighter for ignition waste gas.

E＞ignition time 1～2min, 1150 ± 50 ℃ of ignition temperatures, igniting negative pressure 4000～6000Pa, roasting negative pressure 8000～10000Pa, vertical rate of roasting is controlled at 15～20mm/min.

The present invention utilizes the acidic pellet ore consolidation mechanism, guarantees that the solid phase diffusion of acidic pellet ore is fixed.Pellet is with Fe ₃O ₄Or Fe ₂O ₃The solid phase diffusion of recrystallize is fixed to be main, and the glassiness only accounts for 4～5%, the minute quantity fayalite.Have following advantage: 1. be suitable for medium and small factory and undergo technological transformation, improve the blast furnace burden structure, reduced investment, instant effect is transformed old sinter machine and is got final product, and promotes easily, reduces investment outlay about 85%; 2. output height, energy consumption are low, and utilization coefficient is 1.5～1.7t/m during sinter machine roasting acidic pellet ore ²H, solid fuel consumption 50Kg/tp, and belt type roasting machine utilization coefficient 0.8～1.0t/m only ²H, fuel consumption is 50Kg/tP, i.e. Dwight-Lloyd sintering machine roasting acid pellet output doubles, and energy consumption is suitable; 3. pellet iron (TFe＞60%) of high grade, intensity height (ISO barrate strength 〉=70%), Well-recovered (RI＞55%), the low (RDI of low temperature reduction degradation index _{+ 3.15}〉=75%) intensity good (3.15mm＜20%) after 900 ℃ of reduction.

Description of drawings:

Fig. 1: process flow sheet of the present invention.

Embodiment:

1. (TFe 65.38%, SiO for iron ore concentrate ₂4.8 3%) allocating the pulverized anthracite (1mm accounts for 88.68%) and 20% of 1% wilkinite and 2% again into returns mine behind the mixing, on the dish pelletizer of Φ 1m garden, make ball, green-ball granularity 5～15mm 〉=80%, green-ball moisture 8.5%, green-ball and pulverized anthracite mixing 3min in the tube mixing machine of garden of 2.5%, dry 2min (250 ℃ of drying temperatures in Φ 250mm sintered cup then, dry negative pressure 5000Pa), igniting 2min (1150 ± 50 ℃ of ignition temperatures, igniting negative pressure 4000Pa), roasting negative pressure 8000Pa, bed depth 700mm, vertical rate of roasting is controlled at 14～20mm/min, and under these conditions, pellet output (utilization coefficient) reaches 1.67t/m on the sinter machine ²H, pellet barrate strength (ISO) 〉=70%, yield rate 70～80%, solid fuel consumption 55～60Kg/tp, pellet grade TFe 62.83%, FeO10～13%, reductibility (RI) 55～68%, low-temperature reduction powder rate RDI _{+ 3.15}Intensity-3.15mm is 20% after 80%, 900 ℃ of reduction.

Claims (2)

1. process for making acidic spheroidized ore, comprise batching, make ball, drying, igniting, roasting, fragmentation, screening, it is characterized in that: the present invention is raw material with the high grade iron concentrate, add wilkinite and make binding agent, adopt coal dust directly to allocate bed of material burning into, utilize the acidic pellet ore consolidation mechanism, adopt sinter machine to produce acidic pellet ore, concrete processing parameter is as follows:

A＞use wilkinite is made binding agent, wilkinite proportioning 1.0～2.0% (weight percent), use solid fuel coal dust place of gas fuel or liquid fuel, coal powder size＜3mm, proportioning is 3.5～4.5% (weight percents), and interior coal blending powder proportioning is 1.2～1.5% when wherein making ball;

Outer coal blending powder proportioning is 2.3～3.0% behind d＞the make ball, and employing garden dish pelletizer is made ball, then in the tube mixing machine of garden with coal dust and pelletizing mixing;

C＞green-ball granularity control 5～15mm 〉=80%, green-ball moisture 7.5～10%;

D＞bed depth is 500～700mm, before the igniting roasting dryer section is set, and accounts for 5～20% of roasting time time of drying, and 200～300 ℃ of drying temperatures are thermal source with pellet cooling exhaust or lighter for ignition waste gas;

E＞ignition time 1～2min, 1150 ± 50 ℃ of ignition temperatures, igniting negative pressure 4000～6000Pa, roasting negative pressure 8000～10000Pa, vertical rate of roasting is controlled at 15～20mm/min.

2. method according to claim 1 is characterized in that: described high grade iron concentrate is TFe63～66%, SiO ₂＜5.5% iron ore concentrate.