CN1053221A - Produce the technology of calcium carbide with long-flame coal - Google Patents

Abstract

The invention provides with the long flame raw coal and make the technology that carbon materials is produced calcium carbide.Long-flame coal and unslaked lime are produced calcium carbide by certain proportioning in general furnace of calcium carbide.Improve output, quality, reduce cost about 20%, energy-conservation.

Description

Produce the technology of calcium carbide with long-flame coal

The present invention relates to usefulness long flame raw coal and unslaked lime are produced calcium carbide in electric furnace technology, belong to the technical field of producing calcium carbide.

The calcium carbide production of China generally adopts electric furnace smelting process promptly to use metallurgical coke as carbon materials, and the calcium raw material is selected unslaked lime for use, and two kinds of raw materials drop into electrosmelting by known matching method and produce calcium carbide.But metallurgical coke is the converted products of coal, and the unit price lattice are high and often supply falls short of demand, because it also is the raw material of industries urgent needs such as metallurgical and chemical industry.

According to the retrieval, the overseas utilization electrothermal oven is produced in the technology of calcium carbide, and as Germany and Japan (DE3013726, J56155014 etc.), its carbon materials system adopts hard coal, refinery coke or lean coal.And, participate in reaction with the form of thermal barrier through giving thermal treatment.(J57022111) technology of production compound (as calcium carbide) in closed furnace and for example, employed carbon materials then is a mixture, wherein, coal only accounts for 15% of heavy time ratio.Also must under 600～900 ℃ temperature, heat destructive distillation earlier in process of production.

Purpose of the present invention is to provide the processing method of directly utilizing the long flame raw coal to replace source of goods metallurgical coke in short supply, expensive electrogenesis in next life stone.

Technical characterictic of the present invention is exactly directly to make carbon materials with the long flame raw coal, with known proportioning, electric furnace and repeatedly feeding mode produce calcium carbide.Whole process comprises batching, shove charge, four procedures of operating and come out of the stove, and used electric furnace also can be used for sealed furnace for open stove and semi closed stove.

1, batching

The raw material of producing calcium carbide is unslaked lime and long-flame coal.

Unslaked lime CaO content＞92%

MgO content＜1.6%

Granularity 3～40mm

Optimum value 5～25mm

Long-flame coal total water Mt＜30%

Optimum value＜15%

Butt fixed carbon Cd＞60%

Optimum value＞75%

Dry basis ash content Ad＜20%

Optimum value＜8%

Butt volatile matter Vd＜50%

Optimum value＜40%

Granularity 1～60mm

Optimum value 3～30mm

The proportioning of furnace charge is to obtain by the molecular weight and the known principle of the reaction equation of producing calcium carbide.Be generally the ratio of the unslaked lime 100 and the long flame raw coal of butt.

The reaction formula of producing calcium carbide is as follows:

Consider the composition of unslaked lime, long-flame coal and calcium carbide and the loss that feeds intake, the proportioning calculation formula of furnace charge is as follows:

The content % of A-unslaked lime calcium oxide

The content % of carbide of calcium in the B-calcium carbide

C-long flame raw coal fixed carbon content %

Free calcium oxide content % in the D-calcium carbide

The gas forming amount of free calcium oxide and calcium carbide, the relation of carbide of calcium content:

Calcium carbide gas forming amount (l/kg)	250	260	270	280	290	300	310	320
									Carbide of calcium in the calcium carbide (%)	67.17	69.86	72.86	75.23	77.91	80.86	81.36	84.0
Free calcium oxide (%)	22	20	18	16	14	12	10	8

The loss amount E value of unslaked lime generally gets 7% during the E-shove charge

The loss amount F value of long flame raw coal generally gets 6% during the F-shove charge

Above-mentioned is furnace charge butt proportioning, considers the total water in the long flame raw coal, and ratio formula is:

X=(X _DoTotal water % in the M-long flame raw coal in the formula of)/(1-M)

Unslaked lime and long flame raw coal are mixed the preparation shove charge of even back by the proportioning of calculating.

2, shove charge

According to the capacity of electric furnace with after the gas forming amount that requires to produce calcium carbide calculates the proportioning of furnace charge, by this proportioning metering furnace charge and puddle and evenly deliver to table or magazine, adopt the mode shove charge that repeatedly feeds intake, spare no effort to add less, make the charge level in the stove keep certain height, the charge level profile keeps the steamed bun shape as far as possible.Along with the continuous generation of calcium carbide, furnace charge sinks, and can be clear that 3 circular material feeding mouths around electrode.

3, operation

Calcium carbide production is carried out in furnace of calcium carbide, operates by known furnace operation rules.

High voltage electric is reduced to 60V～100V via furnace transformer, and low-tension current is through short net annealed copper wire, contact tube and conducting jaw plate iontophoresis electrode.With the lifting of windlass control electrode to guarantee needed electric current.Simultaneously, also suitably the lifting electrode relies on arc heat and resistance heat that furnace charge is heated to 1800～2300 ℃ to discharge the CO gas that generates in the stove, in order to keep furnace temperature, should keep arc light not expose.When reinforced, must at first feed intake to the place that open arc is arranged.

4, come out of the stove

Determine per tour number of coming out of the stove by the furnace of calcium carbide capacity.

Under 1800～2300 ℃ high temperature, long-flame coal and unslaked lime carry out chemical reaction and generate calcium carbide.Stopped to feed in raw material in preceding 30～40 minutes coming out of the stove.Suffer all charge level at furnace charge and open arc occurred 20～30 minutes, chemical reaction fully can be come out of the stove.

The also available long-flame coal of the present invention is produced calcium carbide as the part carbon materials.Charge composition is calculated required carbon amount with reference to aforementioned formula, and operation is with aforementioned the same.

Compare with the technology of using the coke production calcium carbide, the present invention has the following advantages:

1, the long-flame coal price lower than coke, can make the calcium carbide production cost reduce about 20%;

2, the content of sulphur, phosphorus lacks than coke in the long-flame coal, can improve the quality of calcium carbide;

3, long-flame coal is bigger than resistance ratio coke, is easy to electrode deeply, processing ease and saves energy;

4, the activity of long-flame coal is bigger, helps improving output;

5, the present invention does not need other standby host tool processing facility directly with the suitable long-flame coal coke for replacing of granularity, has reduced labour intensity, has improved efficiency.

Embodiments of the invention

The calcium carbide that the open electric furnace production gas forming amount that now with the capacity is 1800KVA is 290l/kg is an example, introduces implementation step of the present invention.

1, the raw material of Cai Yonging

The content of unslaked lime CaO: 92%

The content of MgO: 1.6%

Granularity 5～25mm

Long-flame coal total water Mt 15%

Butt fixed carbon 75%

Butt volatile matter 42%

Dry basis ash content 10%

Granularity 3～30mm

2, proportioning is calculated

Calculate the weight proportion of unslaked lime and long-flame coal by aforementioned charge composition formula.

Known: nucleidic mass: C=12 O=16 Ca=40 A=0.92 B=0.7791 C=0.75D=0.14 E=0.07 F=0.06 M=0.15

According to ratio formula

$=\frac{\frac{56.3\÷0.75\×0.7791+0.06}{87.5\÷0.92\×0.7791+0.07+0.14}\×100}{1-0.15}$ $=92.7$

Then the proportioning of unslaked lime and long-flame coal is 100: 92.7

3, shove charge and operation

Be decided to be 2 hour according to the furnace of calcium carbide capacity tap to tap time of every stove calcium carbide.

Mix after acceptable material measured respectively by said ratio, be transported on the boiler face material platform.By feeding intake in the repeatedly reinforced normal direction electric furnace of aforementioned shove charge requirement employing, regulate electrode with windlass and stretch into the length of charge level to keep stable electric current, guarantee that smelting temperature is between 1800～2300 ℃, can not make the operation that feeds intake of processing requirement that arc light exposes by aforementioned, and come out of the stove and stopped to feed in raw material in preceding 30～40 minutes.

4, come out of the stove

Thrown the complete open arc of charge level after 20～30 minutes in furnace charge, the smelting of this stove finishes, and liquid calcium carbide can be come out of the stove, and whole process is 2 hours.

The liquid calcium carbide can carry out fragmentation, packing, check, dispatches from the factory in the electric furnace plug for outlet is banished the calcium carbide cooling pan after the cooling.

Claims (5)

1, a kind of technology of producing calcium carbide is characterized in that directly utilizing the long flame raw coal as carbon materials, produces calcium carbide with unslaked lime in electric furnace.Be limited to 30% on the total water Mt of long flame raw coal, be limited to 60% under the butt fixed carbon Cd content, be limited to 50% on the butt fugitive constituent Vd, be limited to 20% on the dry basis ash content Ad, granularity is 1～60mm.

2, a kind of production calcium carbide technology described in claim 1 is characterized in that being limited to 75% under the butt fixed carbon content Cd optimum value of long flame raw coal, is limited to 40% on the butt volatile content Vd optimum value, is limited to 8% on the butt the ash content of coal Ad optimum value.

3, a kind of production calcium carbide technology described in claim 1 is characterized in that being limited to 15% on the total water Mt optimum value of long flame raw coal.

4, a kind of production calcium carbide technology as claimed in claim 1 is characterized in that long-flame coal granularity optimum value is 3～30mm.

5, a kind of production calcium carbide technology described in claim 1 is characterized in that also available long-flame coal instead of part carbon materials smelting calcium carbide.