阅读说明：本技术 一种锰硅合金低钙渣型冶炼工艺 (Manganese-silicon alloy low-calcium slag type smelting process ) 是由 曾仁福 闫好青 冯选杰 马智 杨旭 王先武 孙伟 高建鹏 于 2021-06-11 设计创作，主要内容包括：本发明公开了一种锰硅合金低钙渣型冶炼工艺,涉及铁合金生产技术领域,以解决低钙渣型下电极裹渣、炉内翻渣、操作炉型缩小、出铁出渣困难、渣铁分离不好、产品质量下降以及负荷给不足的技术问题,本发明包括如下步骤：步骤1、配料准备和入炉冶炼；步骤2、矿热炉内的冶炼控制；步骤3、出炉；步骤4、浇铸；本发明实现低钙渣型下矿热炉稳定顺行、产品质量稳定、生产指标进步的优点。(The invention discloses a manganese-silicon alloy low-calcium slag type smelting process, which relates to the technical field of ferroalloy production and aims to solve the technical problems of low-calcium slag type lower electrode slag wrapping, slag turning in a furnace, reduction of an operation furnace type, difficulty in tapping and slag discharging, poor slag-iron separation, product quality reduction and insufficient load supply, and comprises the following steps: step 1, preparing ingredients and smelting in a furnace; step 2, smelting control in the submerged arc furnace; step 3, discharging; step 4, casting; the invention realizes the advantages of stable and smooth operation of the low-calcium slag type submerged arc furnace, stable product quality and advanced production index.)

1. The manganese-silicon alloy low-calcium slag type smelting process is characterized by comprising the following steps of:

step 1: preparing ingredients and smelting in a furnace: the burdening comprises manganese ore burdening and coke burdening, and the burdening is added into an ore smelting furnace for smelting;

step 2: smelting control in the submerged arc furnace: deeply inserting an electrode in a submerged arc furnace, strengthening electrode voltage discharge, controlling the electrode limit at a middle and lower limit position, operating at high voltage and washing the furnace at regular intervals; the deep insertion electrode can improve the superheat degree of the slag iron and improve the slag iron separation effect, and the high-voltage operation can improve the secondary voltage, enlarge a molten pool and stabilize the electrode to do work;

and step 3: discharging: the double-ladle furnace discharging process is adopted, a furnace eye is opened by an eye opening and blocking machine during furnace discharging, and round steel is adopted for drainage after the furnace eye is opened, so that the furnace discharging speed is accelerated, and the furnace discharging time is shortened; the submerged arc furnace needs to frequently change furnace eyes, so that the hole plugging and mud beating amount is reduced;

and 4, step 4: casting: directly calming for 30-40 minutes when the ladle is taken out of the furnace, carrying out slag skimming on the ladle, and calming for 30-40 minutes after slag skimming is finished; casting a head ladle, passing the two ladles to the head ladle when the head ladle is cast to about the residual 1/5, calming for about 10 minutes and then casting, stopping normal casting when the residual ladle bottom is cast, casting the ladle bottom iron on an ingot mold separately, and finishing and then putting the ingot mold into a finished product.

2. The manganese-silicon alloy low-calcium slag type smelting process according to claim 1, wherein in the step 1, manganese ore ingredients comprise the following components in parts by weight: 35-45 parts of imported manganese ore, 18-25 parts of south African semi-carbonic acid, 13-15 parts of south African high-iron ore, 10-15 parts of self-produced slag and 6-8 parts of dust removal pressure balls; the coke ingredient comprises the following components in parts by weight: 60-70 parts of chemical coke with the granularity of 20-40mm and 30-40 parts of chemical coke with the granularity of 10-30 mm.

3. The manganese-silicon alloy low-calcium slag type smelting process is characterized in that in the coke ingredients, the proportion of chemical coke with the granularity of 20-40mm is 60% -70%, and the proportion of chemical coke with the granularity of 10-30mm is 30% -40% in matched smelting.

4. The manganese-silicon alloy low-calcium slag type smelting process according to claim 1, wherein in the step 2, smelting control comprises strengthening electrode voltage discharge, displacement adjustment and voltage use, and the strengthening electrode voltage discharge and the displacement adjustment can improve the superheat degree, improve the effect of slag-iron separation and prevent slag from turning over in a furnace; the voltage is operated at high voltage, the secondary voltage is increased by 3-5V compared with the secondary voltage under the control of normal slag alkalinity, the arc length and the intensity are increased, a molten pool is enlarged, and abnormal conditions such as unbalanced working force, insufficient load supply and the like caused by electrode slag wrapping are prevented.

5. The manganese-silicon alloy low-calcium slag type smelting process according to claim 1, wherein in the step 2, the furnace washing is performed once every 10 to 15 days in a periodical furnace washing mode, and dolomite, limestone or calcium chloride and the like are used for washing the furnace, so that the reduction of the operation furnace type in the long-time low-calcium slag type smelting is prevented, the furnace condition is worsened, and the index is retreated.

6. The Mn-Si alloy low-calcium slag type smelting process according to claim 4, wherein the high voltage operation requires reduction of coke fraction and the shortage of carbon amount is compensated by inserting an electrode downwards.

7. The manganese-silicon alloy low-calcium slag type smelting process according to claim 1, wherein in step 3, the furnace eye is changed frequently, and the furnace eye is changed from one shift to another or from one furnace to another.

8. The manganese-silicon alloy low-calcium slag type smelting process according to claim 1, wherein in the step 3, the utilization rate of the hole opening and blocking machine is 100%, and the furnace eye channel is prevented from being damaged to influence the discharging.

9. The manganese-silicon alloy low-calcium slag type smelting process according to claim 1, wherein in the step 4, the calming process mainly utilizes the specific gravity difference to enable free carbides and scum in the alloy to float sufficiently, so that the quality of the alloy is improved.

10. The manganese-silicon alloy low-calcium slag type smelting process according to claim 1, wherein in the step 4, the ladle bottom iron is cast separately when 5% -7% of the ladle bottom is left.

Technical Field

The invention relates to the technical field of ferroalloy production, in particular to the technical field of manganese-silicon alloy low-calcium slag type smelting process.

Background

The manganese-silicon alloy is an alloy consisting of manganese, silicon, iron, a small amount of carbon and other elements, and is an iron alloy with wide application and high yield. The manganese-silicon alloy is a compound deoxidizer commonly used for steel making, and is also a reducing agent for producing medium-low carbon ferromanganese and producing metal manganese by an electro-silicothermic method.

According to the silicon-manganese smelting theory and the production practice, the slag form of the slag is mainly calcium slag form in normal condition, the calcium dioxide content in the slag is 20-30%, when the alkalinity of the slag is controlled to be 0.6-0.75, the stability of the furnace condition is good, the index is good, and the alkalinity of most enterprises in the actual production is basically controlled to be more than 0.65, so that the stability of the furnace condition is improved. However, as the content of calcium dioxide in the slag increases, the alkalinity increases and the amount of slag increases accordingly.

Practice shows that: when 1t of manganese-silicon alloy is produced, the slag amount is increased by 10%, the smelting power consumption is increased by about 60-70kWh, and meanwhile, the concentration of a metal reactant is diluted along with the increase of the slag amount, so that the alloy is not beneficial to full reduction, and the production index is influenced. Meanwhile, the high-calcium slag type has serious erosion and chemical erosion to the furnace eye, so that the risk of furnace penetration exists, and the service life of the furnace body of the submerged arc furnace is influenced. The manganese-silicon alloy is smelted by a low-calcium slag type process according to actual starting requirements.

The low-calcium slag type smelting refers to a smelting process with the alkalinity of 0.45-0.55, the content of calcium dioxide in slag is controlled to be 10% -16%, and the content of silicon dioxide in slag needs to be reduced to 29% -32%. However, the smelting process of the low-calcium slag type easily causes the problems of electrode slag wrapping, slag turning in the furnace, furnace shape reduction in operation, difficulty in tapping and slag discharging, poor slag-iron separation, product quality reduction, insufficient load supply and the like.

Disclosure of Invention

The invention aims to: the invention provides a manganese-silicon alloy low-calcium slag type smelting process, aiming at solving the technical problems of low-calcium slag type production of lower electrode slag wrapping, slag turning in a furnace, furnace shape reduction in operation, difficulty in tapping and slag discharging, poor slag-iron separation, product quality reduction and insufficient load.

The invention specifically adopts the following technical scheme for realizing the purpose:

a manganese-silicon alloy low-calcium slag type smelting process comprises the following steps:

step 1: preparing ingredients and smelting in a furnace: the burdening comprises manganese ore burdening and coke burdening, and the burdening is added into an ore smelting furnace for smelting;

step 2: smelting control in the submerged arc furnace: deeply inserting an electrode in a submerged arc furnace, strengthening electrode voltage discharge, controlling the electrode limit at a middle and lower limit position, operating at high voltage and washing the furnace at regular intervals; the deep insertion electrode can improve the superheat degree of the slag iron and improve the slag iron separation effect, and the high-voltage operation can improve the secondary voltage, enlarge a molten pool and stabilize the electrode to do work;

and step 3: discharging: the double-ladle furnace discharging process is adopted, a furnace eye is opened by an eye opening and blocking machine during furnace discharging, and round steel is adopted for drainage after the furnace eye is opened, so that the furnace discharging speed is accelerated, and the furnace discharging time is shortened; the submerged arc furnace needs to be frequently changed, and furnace-to-furnace changing with conditions is achieved, so that the activity of a molten pool in the furnace under a low-calcium slag type is improved, and the stability of furnace conditions is improved; the hole-blocking mud-applying amount is reduced, and the control is carried out according to 80-90% of the mud-applying amount under the normal alkalinity, so as to create conditions for opening the furnace hole.

And 4, step 4: casting: directly calming for 30-40 minutes when the ladle is taken out of the furnace, carrying out slag skimming on the ladle, and calming for 30-40 minutes after slag skimming is finished; casting a head ladle, passing the two ladles to the head ladle when the head ladle is cast to about the residual 1/5, calming for about 10 minutes and then casting, stopping normal casting when the residual ladle bottom is cast, casting the ladle bottom iron on an ingot mold separately, and finishing and then putting the ingot mold into a finished product.

Further, in the step 1, the manganese ore comprises the following components in parts by weight: 35-45 parts of imported manganese ore (manganese ore, brazil or galauum manganese ore), 18-25 parts of south African semi-carbonic acid, 13-15 parts of south African high-iron ore, 10-15 parts of self-produced slag and 6-8 parts of dust removal pressure balls; the coke ingredient comprises the following components in parts by weight: 60-70 parts of chemical coke with the granularity of 20-40mm and 30-40 parts of chemical coke with the granularity of 10-30 mm. The south African high-iron ore is a manganese ore with high iron content, and the self-produced slag is a byproduct in manganese-silicon alloy smelting.

Further, the chemical coke with the granularity of 20-40mm accounts for 60% -70%, and the chemical coke with the granularity of 10-30mm accounts for 30% -40% for matching smelting; in the prior art, the chemical coke granularity is 20-40mm, and the arrangement of the proportion in the scheme is beneficial to inserting the electrode downwards after reducing the coke granularity, so that the operation requirement of the deep electrode in the step 2 is met; secondly, carbon for reduction at the upper part of furnace burden is ensured, the thickness of residual carbon layer at the bottom of the furnace is ensured to be reasonable, and the alloy reduction degree is promoted; and thirdly, the carbon discharge amount of the furnace eye can be reduced after the particle size fraction of the coke is reduced, and the front tapping of the furnace is facilitated.

Further, in the step 2, smelting control comprises strengthening electrode voltage discharge, displacement adjustment and voltage use, wherein the strengthening electrode voltage discharge and the displacement adjustment can improve the superheat degree, improve the effect of slag-iron separation and prevent slag from turning over in the furnace; the voltage is operated at high voltage, the secondary voltage is increased by 3-5V compared with the secondary voltage under the control of normal slag alkalinity, the arc length and the intensity are increased, a molten pool is enlarged, and abnormal conditions such as unbalanced working force, insufficient load supply and the like caused by electrode slag wrapping are prevented.

Further, in the step 2, the furnace washing is carried out once every 10-15 days in a regular furnace washing mode, dolomite, limestone or calcium chloride and the like are adopted for washing the furnace, the reduction of the operating furnace type in long-time low-calcium slag type smelting is prevented, the furnace condition is worsened, and the index is retreated.

Further, in step 2, the high voltage operation requires the reduction of coke fraction, and the shortage of carbon amount is compensated by inserting the electrode downwards.

Further, in step 3, the furnace eye is changed frequently, in principle, according to one shift and one eye or one furnace and one eye.

Furthermore, in the step 3, the utilization rate of the hole opening and blocking machine is 100%, and the furnace eye channel is prevented from being damaged to influence the discharging.

Furthermore, in the step 4, the sedation process mainly utilizes the specific gravity difference to lead the free carbide and the scum in the alloy to float sufficiently, thereby improving the quality of the alloy.

Further, in the step 4, the ladle bottom iron is independently cast when 5% -7% of the ladle bottom is required to be left, so that the quality reduction caused by mixing of the final slag iron mixture into a finished product is prevented.

The invention has the following beneficial effects:

1. in the invention, in the general production process, the problems of electrode slag wrapping, slag turning, unsmooth slag discharging and the like in the low-calcium slag type smelting process cause insufficient load, large smelting parameter difference, reduced productivity and gradually worsened furnace conditions; by combining theory and practice, the process is optimized from source to combination, the smelting system under the low-calcium slag type is matched, the influence caused by the low-calcium slag type is effectively solved, the slag quantity is greatly reduced, the slag-iron ratio is improved, the stability of the furnace condition is improved, and the index progress is obvious.

2. Under the normal production condition, because the alkalinity is reduced, the furnace front is difficult to open, the furnace tapping time is generally more than 25 minutes, after the process optimization, the furnace tap can be directly drilled, and the furnace tapping time is 10-15 minutes.

3. After the process is implemented, the quality exchange rate of the alloy is improved by more than 10%, and the problem of high sulfur and high carbon of the alloy is effectively solved.

4. After the process is implemented, the slag-iron ratio is reduced to be within.73 from 0.85, the smelting power consumption is reduced by more than 50kwh/t, and the recovery rate of the manganese element is increased by more than 1%.

5. Effectively solves the furnace eye perforation and furnace body accidents and realizes the safe operation of the furnace body.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments.

Example 1

A manganese-silicon alloy low-calcium slag type smelting process comprises the following steps:

step 1: preparing ingredients and smelting in a furnace: the burdening comprises manganese ore burdening and coke burdening, and the burdening is added into an ore smelting furnace for smelting;

step 2: smelting control in the submerged arc furnace: deeply inserting an electrode in a submerged arc furnace, strengthening electrode voltage discharge, controlling the electrode limit at a middle and lower limit position, operating at high voltage and washing the furnace at regular intervals; the deep insertion electrode can improve the superheat degree of the slag iron and improve the slag iron separation effect, and the high-voltage operation can improve the secondary voltage, enlarge a molten pool and stabilize the electrode to do work;

and step 3: discharging: the double-ladle furnace discharging process is adopted, a furnace eye is opened by an eye opening and blocking machine during furnace discharging, and round steel is adopted for drainage after the furnace eye is opened, so that the furnace discharging speed is accelerated, and the furnace discharging time is shortened; the submerged arc furnace needs to be frequently changed, and furnace-to-furnace changing with conditions is achieved, so that the activity of a molten pool in the furnace under a low-calcium slag type is improved, and the stability of furnace conditions is improved; the hole-blocking mud-applying amount is reduced, and the control is carried out according to 80-90% of the mud-applying amount under the normal alkalinity, so as to create conditions for opening the furnace hole.

And 4, step 4: casting: directly calming for 30-40 minutes when the ladle is taken out of the furnace, carrying out slag skimming on the ladle, and calming for 30-40 minutes after slag skimming is finished; casting a head ladle, passing the two ladles to the head ladle when the head ladle is cast to about the residual 1/5, calming for about 10 minutes and then casting, stopping normal casting when the residual ladle bottom is cast, casting the ladle bottom iron on an ingot mold separately, and finishing and then putting the ingot mold into a finished product.

Further, in the step 1, the manganese ore comprises the following components in parts by weight: 35-45 parts of imported manganese ore (manganese ore, brazil or galauum manganese ore), 18-25 parts of south African semi-carbonic acid, 13-15 parts of south African high-iron ore, 10-15 parts of self-produced slag and 6-8 parts of dust removal pressure balls; the coke ingredient comprises the following components in parts by weight: 60-70 parts of chemical coke with the granularity of 20-40mm and 30-40 parts of chemical coke with the granularity of 10-30 mm.

Further, the chemical coke with the granularity of 20-40mm accounts for 60% -70%, and the chemical coke with the granularity of 10-30mm accounts for 30% -40% for matching smelting; in the prior art, the chemical coke granularity is 20-40mm, and the arrangement of the proportion in the scheme is beneficial to inserting the electrode downwards after reducing the coke granularity, so that the operation requirement of the deep electrode in the step 2 is met; secondly, carbon for reduction at the upper part of furnace burden is ensured, the thickness of residual carbon layer at the bottom of the furnace is ensured to be reasonable, and the alloy reduction degree is promoted; and thirdly, the carbon discharge amount of the furnace eye can be reduced after the particle size fraction of the coke is reduced, and the front tapping of the furnace is facilitated.

In the step 2, smelting control comprises strengthening electrode voltage discharge, displacement adjustment and voltage use, wherein the strengthening electrode voltage discharge and the displacement adjustment can improve the superheat degree, improve the effect of slag-iron separation and prevent slag from turning over in the furnace; the voltage is operated at high voltage, the secondary voltage is increased by 3-5V compared with the secondary voltage under the control of normal slag alkalinity, the arc length and the intensity are increased, a molten pool is enlarged, and abnormal conditions such as unbalanced working force, insufficient load supply and the like caused by electrode slag wrapping are prevented.

In the step 2, the furnace washing is carried out once every 10 to 15 days in a regular furnace washing mode, dolomite, limestone or calcium chloride and the like are adopted for washing the furnace, the reduction of an operation furnace type in long-time low-calcium slag type smelting is prevented, the furnace condition is worsened, and the index is retreated.

In step 2, the coke particle size fraction needs to be reduced in high-voltage operation, and the shortage of carbon amount is made up by inserting electrodes downwards.

In step 3, the furnace eye is changed frequently, and the furnace eye is changed on a one-shift-one-eye basis or on a one-furnace-one-eye basis in principle.

In the step 3, the utilization rate of the hole opening and blocking machine is 100%, and the furnace eye channel is prevented from being damaged to influence the discharging.

In the step 4, the calming process mainly utilizes the specific gravity difference to enable free carbide and scum in the alloy to float sufficiently, so that the quality of the alloy is improved.

And 4, performing independent casting when the bottom iron of the ladle is independently cast and the residual 5-7 percent of the bottom iron of the ladle is required, so as to prevent the final slag iron mixture from being mixed into a finished product to cause quality reduction.

Example 2

A manganese-silicon alloy low-calcium slag type smelting process is refined on the basis of the embodiment 1 as follows:

(1) the manganese ore comprises the following components in parts by weight: 20 parts of manganese ore, 25 parts of peruvian manganese ore, 20 parts of semi-carbonic acid in south Africa, 15 parts of high iron ore in south Africa, 12 parts of self-produced slag and 8 parts of dust removal dust pressing balls; the coke ingredient comprises the following components in parts by weight: 65 parts of chemical coke with the granularity of 20-40mm and 35 parts of chemical coke with the granularity of 10-30 mm. The carbon distribution amount is adjusted down by 10kg on a normal basis.

(2) And (3) inserting the electrode deeply, limiting the electrode at the middle and lower limit positions, increasing the pressure discharge by 20-30 mm/day, and increasing the temperature of the submerged arc furnace, specifically, increasing the temperature of molten iron in the submerged arc furnace from 1520-1530 ℃ to more than 1540 ℃.

(3) High voltage operation, secondary voltage increased from 210V to 215V.

(4) And (4) washing the furnace by adopting dolomite every 10 days for one day. The dosage of dolomite is 40 kg/batch.

(5) And (4) after the furnace is taken out, the furnace is calmed for 35 minutes, and the ladle bottom iron is cast separately when 6 percent of the ladle bottom iron is left.

(6) The furnace eye is changed from one class to another.

In the embodiment, the furnace condition stability is good, the slag-iron ratio is 0.70, the average daily output is increased to 141t from about 140t, the smelting power consumption is reduced to 4030kwh/t from 4080kwh/t, the recovery rate is increased to 88.6% from 85.6%, the alloy quality is increased to 98% from 88%, and the improvement of the alloy quality and the economic and technical indexes is realized on the basis of stabilizing the furnace condition.

Example 3

A manganese-silicon alloy low-calcium slag type smelting process is refined on the basis of the embodiment 1 as follows:

(1) the manganese ore comprises the following components in parts by weight: 22 parts of pyrolusite, 23 parts of bigalite, 18 parts of semi-carbonic acid in south Africa, 16 parts of high iron ore in south Africa, 15 parts of self-produced slag and 6 parts of dust removal dust pressing balls; the coke ingredient comprises the following components in parts by weight: 70 parts of chemical coke with the granularity of 20-40mm and 30 parts of chemical coke with the granularity of 10-30 mm. The carbon distribution amount is adjusted to 8kg on a normal basis.

(2) And (3) inserting the electrode deeply, limiting the electrode at the middle-lower limit position, increasing the pressure discharge by 30-40 mm/day, and increasing the temperature of the submerged arc furnace, specifically, increasing the temperature of molten iron in the submerged arc furnace from 1520-1530 ℃ to more than 1535 ℃.

(3) High voltage operation, secondary voltage increased from 210V to 213V.

(4) Washing the furnace with dolomite every 12 days for 2 days. The dosage of dolomite is 45 kg/batch.

(5) And (4) after the steel is taken out of the furnace, the steel is calmed for 40 minutes, and the steel is cast separately when 8 percent of the steel at the bottom of the ladle remains.

(6) The furnace eye is changed from furnace to furnace.

In the embodiment, the furnace condition stability is good, the slag-iron ratio is 0.71, the average daily output is increased to 140.5t from about 140t, the smelting power consumption is reduced to 4025kwh/t from 4080kwh/t, the recovery rate is increased to 88.9% from 86.2%, the alloy quality is increased to 95% from 85%, and the improvement of the alloy quality and the economic and technical indexes is realized on the basis of stabilizing the furnace condition.