JP2010007135A - Horizontal-type rotary kiln for sulfurizing and refining, and method for sulfurizing-refining copper-dross using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary kiln for sulfurizing and refining and a method for sulfurizing and refining copper dross using the kiln, with which while preventing local over-heat in the rotary kiln, melting time can be shortened. <P>SOLUTION: The rotary kiln for sulfurizing and refining for separating the copper from lead as copper-sulfide from copper dross includes: a high-pressure burner having a nozzle so as to blow generated flame into the kiln at a furnace nose; and an oxygen-blowing pipe for blowing pure oxygen, which has an opening part near the nozzle separately from the high pressure burner. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a horizontal rotary furnace used in a sulfidation purification process for separating copper from copper dross containing copper and lead as copper sulfide, and a method for sulfidation purification of copper dross using the same.

  There is an ISP (Imperial Smelting Process) method as a method of simultaneously refining lead and zinc from a raw material containing lead and zinc and recovering lead and zinc. In the ISP method, sinter obtained by oxidizing and roasting raw materials and coke as a reducing agent and a heat source are alternately charged into a blast furnace. The charged sinter is heated and reduced with the coke combustion by the hot air blown into the blast furnace, and zinc rises with the furnace gas as steam and enters the lead splash condenser at about 1000 ° C. from the top of the furnace.

  A large amount of molten lead is stored in the lead splash condenser, and a large amount of lead splash is generated by the stirrer. When the gas passes through the lead splash condenser, the zinc vapor in the gas comes into contact with the lead splash, and the zinc vapor is rapidly condensed and dissolved in the lead.

  Thereafter, the molten lead in the splash condenser is pumped up, sent to a cooling trough, phase separated, zinc is recovered, and lead is returned to the splash condenser.

  On the other hand, the lead in the raw material is melted in the blast furnace, taken out from the bottom of the blast furnace together with slag to the front floor as crude lead, and separated.

  Since the obtained crude lead contains valuable materials such as copper, gold, and silver, for example, put it in a copper removal pan and scoop up the dross that has been lifted by vigorously stirring the lead with a stirrer each time. And is separated into copper dross and crude lead (see Patent Document 1).

  This is because during the process of cooling the molten crude lead, separation occurs due to the difference between the density of the phase rich in copper and other impurities and the density of lead, and the phase rich in impurities rises, causing dross Take advantage of forming. The crude lead thus obtained is subjected to electrolytic purification.

  On the other hand, since copper dross contains a lot of lead, sulfur and soda ash, iron, powdered coke, etc. are added and dissolved using a reflection furnace, horizontal rotary furnace, etc., and the sulfide is separated from copper as copper sulfide. It is used for the purification process.

  There are various types of horizontal rotary furnaces (see, for example, Patent Document 2 and Patent Document 3), but the horizontal rotary furnace used in the sulfidation purification process basically has the same structure. Specifically, as shown in FIG. 2, the horizontal rotary furnace 1 includes a furnace body 2 (for example, an outer diameter: 3.3 m, a length of 4 m) made of a cylindrical body lined with a refractory material. A furnace port 3 that also serves as a burner port and an exhaust port is provided on one end side. Further, a hot water outlet (not shown) is provided on a part of the outer periphery of the furnace body 2. The furnace body 2 is supported by a support roller (not shown) and is rotated at a predetermined rotational speed.

  A high-pressure burner 4 is disposed at the furnace port 3 toward the inside of the furnace body 2. The high pressure burner 4 is supplied with fuel such as heavy oil and gas and air including secondary air in an amount necessary for secondary combustion by a fan (not shown), and is supplied by the high pressure burner 4 with flame, fuel gas and Air is blown into the furnace.

  Further, on the furnace port 3 side, a flue (not shown) having an inlet disposed so as to cover the furnace port 3 is installed.

  In the copper dross sulfidation purification process using such a horizontal rotary furnace 1, the flame of the high pressure burner 4 is blown into the furnace while rotating the furnace body 2, and the flame and fuel gas introduced through the high pressure burner 4. With the secondary air, the furnace bricks and the copper dross in the furnace are uniformly maintained in the range of 850 ° C to 900 ° C. Then, melting of copper dross in the furnace is promoted, and copper in the copper dross is separated and recovered as copper sulfide and lead as crude lead. During this time, the exhaust gas is discharged from the opening 3 through the flue. In addition, the obtained copper sulfide is normally processed in a copper smelting process.

  In the sulfidation purification step, it is important to heat and dissolve the contents in the furnace smoothly, stir the contents by rotation of the furnace body 2, and uniformly raise the contents to a predetermined temperature.

  However, since copper dross is processed using such a horizontal rotary furnace 1, the temperature inside the furnace is increased to a predetermined temperature by about 10 hours due to heat loss of the furnace body radiated heat and exhaust gas removal sensible heat. There is a problem that it takes time.

  By using an oxygen burner that supplies pure oxygen instead of a high-pressure burner as a means for solving such a problem, exhaust gas can be carried away and sensible heat can be reduced.

However, when only pure oxygen is supplied to the high-pressure burner 4, the generated flame is shortened to a length of about 1.5 m and a short flame, so the vicinity of the furnace port 3 of the horizontal rotary furnace 1 is locally heated, Thereby, brick melting of the furnace body 2 occurs, and periodic repairs are necessary, which increases the cost. Moreover, the furnace volume of the furnace body 2 decreases due to the local heating of the high melting point oxide due to the local heating, and as a result, there is a problem that the amount of copper dross processed decreases.
Japanese Patent Laid-Open No. 4-224439 Japanese Patent Laid-Open No. 2001-3122 JP 7-70662 A

  An object of the present invention is to solve the above-described problems, and to prevent the local heating of the horizontal rotary furnace and to reduce the melting time, and to provide a sulfur furnace for refining purification and a copper using the same. It is to provide a dross sulfidation purification method.

  The present invention relates to a horizontal rotary furnace for sulfidation purification for separating copper from copper dross as copper sulfide and lead and a method for sulfidation purification of copper dross using the same.

  In particular, the horizontal rotary furnace for sulfidation purification according to the present invention is provided with a cylindrical furnace body having a furnace port at one end and a nozzle provided in the vicinity of the furnace port, and flame and fuel gas are directed from the nozzle into the furnace. A high-pressure burner to be blown, and a high-pressure burner separated from the high-pressure burner, having a blow-off port in the vicinity of the nozzle, and an oxygen blow-in tube for blowing pure oxygen from the blow-in port into the furnace. And

  It is preferable to further include a structure for fixing the orientation and position of the oxygen blowing tube in an adjustable manner.

  Moreover, it is preferable that a protective tube is provided on all or part of the outer periphery of the oxygen blowing tube. The protective tube is preferably made of stainless steel.

  A method for sulfidizing and purifying copper dross according to the present invention uses the horizontal rotary furnace for sulfidizing and refining at least the amount of pure oxygen necessary for secondary combustion of the fuel gas in the furnace while melting copper dross. It supplies to the vicinity of the nozzle of the said high pressure burner by the oxygen blowing pipe | tube. At this time, the amount of air supplied to the high-pressure burner is reduced.

  With the horizontal rotary furnace for sulfidation purification of the present invention, in the sulfidation purification process of copper dross, while the copper dross is melted, pure oxygen in an amount necessary for secondary combustion is blown into the vicinity of the nozzle of the high pressure burner. Compared with a horizontal rotary furnace using a burner, the flame temperature can be raised, and at the same time, the amount of secondary air can be reduced. Therefore, since the amount of exhaust gas can be reduced, it is possible to significantly reduce the sensible heat that the exhaust gas is taken away.

  On the other hand, in the horizontal rotary furnace according to the present invention, since a high pressure burner is used, unlike the horizontal rotary furnace using an oxygen burner, shortening of the flame is not recognized. Etc. can be reduced.

  As a result, it is possible to shorten the melting time while avoiding problems due to local heating of the rotary furnace, shortening the operation time, increasing the amount of copper dross treatment, and effective operating unit by using pure oxygen It is possible to reduce the outage loss for repair and repair by melting the brick of the furnace body.

  The present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the horizontal rotary furnace of the present invention.

  The horizontal rotary furnace 1 for sulfidation purification of the present invention comprises a furnace body 2 composed of a cylindrical body lined with a refractory material such as refractory bricks, and a furnace opening serving as a burner port and an exhaust port at one end side of the furnace body 2. 3 is provided. A horizontal rotary furnace 1 used for sulfidation purification of copper dross generally has an outer diameter of 3.3 m, a length of 4 m, and an iron furnace body.

  As in the prior art, a hot water outlet (not shown) is provided on the outer periphery of the furnace body 2 and is supported by a support roller (not shown) so as to rotate at a predetermined rotational speed.

  A high-pressure burner 4 is disposed at the furnace port 3 toward the inside of the furnace body 2. The high-pressure burner 4 is supplied with fuel such as heavy oil and gas and secondary air in an amount required for secondary combustion by a fan (not shown), and is supplied from a nozzle provided near the furnace port 3 from a flame, Fuel gas and secondary air are blown into the furnace. However, the flow rate of supplied air can be limited by an adjusting mechanism such as a valve.

  Further, on the furnace port 3 side, a flue (not shown) having an inlet disposed so as to cover the furnace port 3 is installed.

  The horizontal rotary furnace 1 of the present invention includes an oxygen blowing pipe 5 for blowing pure oxygen, which is separated from the high pressure burner 4 and has an opening in the vicinity of the nozzle of the high pressure burner 4.

  The oxygen blowing pipe 5 is a stainless steel pipe, and is connected to an oxygen supply source such as a general-purpose oxygen cylinder or an oxygen plant on the supply side. Here, “pure oxygen” refers to industrial oxygen and the like.

  This oxygen blowing pipe 5 is provided in the vicinity of the nozzle of the high-pressure burner 4 as shown in FIG. Moreover, it is preferable to provide a structure for fixing the orientation and position of the oxygen blowing tube 5 so as to be adjustable. This structure may be any known technique such as attachment means using mechanical parts. With this structure, the oxygen blowing angle and blowing position can be arbitrarily adjusted.

  In operation, the amount of secondary air supplied from the high-pressure burner 4 to the furnace is reduced at least from the start of dissolution of the copper dross until it completely dissolves. Supply oxygen.

  The injection of pure oxygen from the oxygen blowing pipe 5 makes it possible to increase the flame temperature during supply. In addition, the length of the flame generated from the high-pressure burner can be appropriately adjusted, and the heat distribution in the furnace can be made uniform. Therefore, the flame shortening can be suppressed and brick melting of the furnace body due to local overheating near the furnace port of the rotary furnace can be suppressed.

  Furthermore, since the amount of oxygen required for secondary combustion is reduced from the supply amount of air as secondary air required for it, the amount of exhaust gas can be reduced. Therefore, it is possible to reduce the sensible heat by removing exhaust gas.

  In the horizontal rotary furnace 1 of the present invention, a protective tube 6 is provided on all or part of the outer periphery of the oxygen blowing tube 5. The protective tube 6 functions to prevent damage to the oxygen blowing tube 5. The material of the protective tube 6 is preferably stainless steel such as SUS or refractory in consideration of heat resistance and corrosion resistance.

  Note that the oxygen blowing position by the oxygen blowing pipe 5 is set near the flame of the high-pressure burner 4 in order to avoid the necessity of penetrating the furnace body 2 when the protective pipe 6 is provided in the horizontal rotary furnace 1. Because.

  Further, while the copper dross is melted, the horizontal rotary furnace 1 is kept stationary, and after the copper dross is melted, the horizontal rotary furnace 1 is rotated to perform an operation for promoting the copper sulfidation reaction. Therefore, it is preferable that the tip of the protective tube is positioned in the vicinity of the nozzle of the high-pressure burner so that the tip of the oxygen blowing tube 5 can be extended in the axial direction of the furnace body. When such an operation is not required, the tip of the protective tube may be set at an arbitrary position.

Example 1
The horizontal rotary furnace according to the present invention was operated on a trial basis, and the operation time, the amount of copper dross treated, the basic unit of operation, and the effect of the outage loss due to repair were investigated.

  Into a horizontal rotary furnace (outer diameter 3.3 m, length 4 m) made of a furnace body lined with refractory bricks, 9.5 tons of copper dross and a solvent were charged. The amount of the solvent was adjusted according to the copper quality of the copper dross and the quality of the sulfided mat to be refined, and was 2.4 tons in this example.

  When heating with a high pressure heavy oil burner having a heavy oil consumption of 110 to 140 L / hr, the oxygen blowing pipe is adjusted until the copper dross is completely dissolved from the start of temperature rise while adjusting the direction and position of the oxygen blowing pipe. From this, 500 liters / minute of industrial oxygen in a cylinder was introduced as pure oxygen. During this period, the amount of air supplied to the high-pressure heavy oil burner was reduced. Complete dissolution of copper dross was confirmed by in-furnace scale. The time from the start of temperature increase to the dissolution of copper dross was 3 hours.

  After that, the supply of industrial oxygen was stopped, and the high-pressure heavy oil burner was supplied with air pressurized by an air fan as secondary air, and heating with the high-pressure heavy oil burner was continued, and the copper in the furnace was changed to copper sulfide. .

  The time required for one operation was 10 hours from the start of temperature elevation to the end of the sulfurization purification. As a result, 4 tons of copper sulfide and 5 tons of crude lead were obtained.

  When the operation of the horizontal rotary furnace described above was continued for 3 months, in the method using the horizontal rotary furnace of the present invention, the entire operation was achieved by shortening the melting time as compared with the conventional case using the atmosphere as secondary air. The time was reduced by about 1 hour. Moreover, the amount of copper dross processed per month was 400 tons, which is higher than that of the conventional method.

(Comparative Example 1)
The horizontal rotary furnace was experimentally operated for 3 months in the same manner as in Example 1 except that a pure oxygen burner was used instead of the high-pressure heavy oil burner.

  Compared with Example 1, the melting time was shortened by about 2 hours at the maximum, but local overheating occurred, and the furnace volume was reduced due to brick melting of the rotary furnace body and refractory oxide in the furnace. The total amount of copper dross and solvent that can be charged is about 7 tons. As a result, the monthly throughput of copper dross has been reduced to 350 tons.

  On the other hand, in Example 1 using the horizontal rotary furnace of the present invention, the heat distribution in the furnace becomes uniform, and refractory oxide deposition occurs in the furnace due to local overheating, and the furnace volume decreases. It is understood that the amount of copper dross treated can be improved by preventing both occurrences.

  The amount of pure oxygen used was about 30% as compared with Comparative Example 1 using a pure oxygen burner. As a result, it is understood that a reduction in the basic unit of operation can also be achieved. Furthermore, it is understood that the outage loss and the repair cost can be reduced by repairing the furnace body due to the melted brick.

FIG. 1 is a perspective view showing an embodiment of a horizontal rotary furnace of the present invention. FIG. 2 is a perspective view showing a conventional example of a conventional horizontal rotary furnace.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Horizontal rotary furnace 2 Furnace body 3 Furnace port 4 High pressure burner 5 Oxygen blowing pipe 6 Protection pipe

Claims (5)

A horizontal rotary furnace for sulfur purification for separating copper from copper dross as copper sulfide with lead,
A cylindrical furnace body having a furnace port at one end, a nozzle provided in the vicinity of the furnace port, a high pressure burner for blowing flame and fuel from the nozzle into the furnace, and the high pressure burner are separated from each other, A horizontal rotary furnace for sulfidation purification, comprising an injection port in the vicinity of the nozzle, and an oxygen injection pipe for injecting pure oxygen from the injection port into the furnace.   The horizontal rotary furnace for sulfidation purification according to claim 1, comprising a structure for fixing the orientation and position of the oxygen blowing pipe in an adjustable manner.   The horizontal rotary furnace for sulfidation purification according to claim 1 or 2, wherein a protective tube is provided on all or part of the outer periphery of the oxygen blowing tube.   The horizontal rotary furnace for sulfuration purification according to any one of claims 1 to 3, wherein the protective tube is made of stainless steel. A method for sulfidation purification of copper dross using the horizontal rotary furnace for sulfidation purification according to any one of claims 1 to 4,
At least during the melting of copper dross, instead of the secondary air sent into the furnace, pure oxygen in an amount necessary for secondary combustion of the fuel gas in the furnace is supplied to the nozzle of the high-pressure burner by the oxygen blowing pipe. To sulfidize copper dross to be supplied in the vicinity.

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