JPS60131933A - Refining device for gold - Google Patents

Abstract

PURPOSE:To refine gold at a small flow rate of a refining gas in a short time and to improve the purity thereof by blowing the refining gas with a uniform distribution to the surface of the molten gold in a crucible. CONSTITUTION:Gold A having 99.5-99.6% is put into an Al2O3 crucible 3 in an electric furnace 1 and is heated to melt by a heater 2. Gaseous Cl or gaseous Cl contg. O2 is blown through a gas blow quartz pipe 4 attached with an inverted funnel-shaped blow port 4' to the surface of the molten gold A. The max. diameter at the bottom end of the port 4' is made slightly smaller than the bore of the crucible 3 and the space from the surface of the molten gold A is made to 1-10mm.. The refining gas such as Cl is uniformly distributed and blown to the surface of the molten gold A, then the impurities in the gold and a part of the gold evaporate in the form of chloride and stick in the form of a crystal (a) on the inside wall of a cooling cylinder 5. The molten gold is refined to 99.999% purity. The gold chloride sticking on the inside wall of the cylinder 5 is recovered by washing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gold refining apparatus, specifically, a gold refining device that sprays refining gas (chlorine gas or a combined gas of chlorine and oxygen) onto the surface of molten gold in a melting crucible through a gas blowing pipe. This invention relates to improvements in purification equipment.

In the conventional apparatus, no consideration was given to the gas blowing means, and purified gas was simply blown into the melting crucible from the gas blowing pipe.

However, not only does it take a long time to purify the process, resulting in poor workability, but also the purity is only about 99.5 to 99.6%, and the purified gas is often blown into the process. The disadvantage is that the amount of gold volatilization is large.

Further, since the conventional apparatus is an open type, it is difficult to recover volatilized gold and chloride, and toxic and corrosive chlorine gas is scattered, resulting in deterioration of environmental hygiene.

In view of such conventional circumstances, the present invention aims to provide high-purity gold (99,999%) with good workability by improving the apparatus to shorten the required time and increase the reaction effect with a small gas supply amount. Where the purpose is to do something, and where it is for other purposes, it is volatile money,
The objective is to facilitate the recovery of chlorides, ensure the treatment of chlorine gas, and ensure environmental hygiene.

A first aspect of the present invention is to provide an inverted funnel-shaped inlet at the tip of a gas blowing pipe, and to spray purified gas uniformly onto the surface of molten metal from the inlet, In addition to the structure, the second invention is that the top of the melting crucible is covered by a cooling cylinder that communicates with the exhaust duct.

To explain the present invention with reference to the drawings, in FIG.
) is an electric furnace, (2) is a heating heater, (3) is a melting crucible, (4) is a gas blowing pipe, (5) is a cooling cylinder, and (6) is an exhaust duct.

The melting crucible (3) is heated by the heating heater (2) to melt the gold ingot and obtain molten gold (A).

A high frequency coil (2') may be used as the heat source instead of the heater (2) (FIG. 2).

An elevating rod (7) is attached to the melting crucible (3) below the bottom so that it can move up and down, and the elevating rod (7)
) to move up and down.

As the dissolution crucible (3), an alumina crucible or the like which does not react with chlorine or chloride is used.

The gas blowing pipe (4) is made of quartz, passes through the side wall of the cooling cylinder (5), hangs down into the crucible (3), and has a blowing port (4') integrally formed at its lower end.

The inlet (4') is formed in the shape of an inverted funnel that widens at the bottom, and the maximum diameter at its lower end is a predetermined minimum diameter smaller than the inner diameter of the crucible (3).

The gap (]1) between the blowing port (4') and the molten metal (A) is set in the range of 1 to 10 mm.

The gas blowing pipe (4) is connected to a tank (not shown) containing purified gas (chlorine gas or a mixed gas of chlorine and oxygen), and the gas (b) is injected into the crucible ( 3) Blow the surface of the molten gold (A) inside.

The above-mentioned gap (h) is selected to be the optimum value within the above range according to the inner diameter of the injection port (4') and the crucible (3), and the gas injection amount, and the selected gap (11) is kept constant during the refining operation. In order to maintain the temperature, the crucible (3) is moved up by a minute amount using the lifting rod (7) in accordance with the descent of the surface of the molten metal (A).

The cooling cylinder (5) is installed on the electric furnace (1) and the crucible (
3) The upper part is covered, and a channel (8) through which a refrigerant such as water flows is formed on the side wall, an inflow pipe (9) is provided at the lower end of the channel (8), and a discharge pipe (9) is provided at the upper end of the channel (8). 9') are connected.

The cylinder wall of the cooling cylinder (5) is cooled by circulating a refrigerant through the flow path (8).

An exhaust duct (6) is connected to the upper end of the cooling cylinder (5), and the inside of the cooling cylinder (5) is appropriately suctioned through the duct (6).

Then, the gold ingot is melted in the crucible (3), and the molten gold (A)
After producing the molten gold (A), the purified gas (b) is blown onto the surface of the molten gold (A) for a predetermined period of time from the inlet (4') of the blowing pipe (4) to purify the molten gold (A).

The purified gas (b) is passed through the inlet (4') to the molten gold (A).
It is blown into the surface evenly and efficiently causes a substitution reaction.

During refining work, unnecessary impurities in the gold and a small amount of gold are gasified and volatilized as chlorides from inside the crucible (3), but these chlorides are cooled while rising inside the cooling cylinder (5). It condenses and adheres to the inner wall of the cooling cylinder (5) as crystals (a).

After the refining work, the cooling cylinder (5) is washed with water, and the gold is recovered from the gold chloride solution in the crystal (a) and covered.

Note that the chloride that has not adhered to the inside of the cooling cylinder (5) can be freely collected in the exhaust duct (6), and the chloride gas component in the volatilized chloride can be recovered after passing through the exhaust duct (6). ,
Or clean the exhaust duct with caustic soda.

Next, examples will be shown.

The crucible (3) has an inner diameter of 9QlIlIiφ and a height of 2
00 mm, and the cooling tube (5) is 800 mm, 10 KCI of gold ingots are heated to about 120 KCI by a high frequency coil.
Molten gold (A) is produced by heating to 0°C.

Next, the gap between the injection port (4') and the surface of the molten metal (A) is set to 3.
mm, and purified gas (mixed gas of chlorine:oxygen=1=1) was blown into the tank from the blowing port (4') for about 20 minutes for purification.

As a result, gold with a purity of 99.5% became 99.998% pure.

After further purification for 10 minutes, purity 99.999
% of gold was obtained.

After the refining work, the cooling cylinder (5) was washed with water and about 30 g of gold was recovered.

In the present invention, as in the first invention described above, an inverted funnel-shaped inlet is provided at the tip of the gas blowing pipe and is opposed to the surface of the molten metal with a gap therebetween, so that purified gas is uniformly distributed from the inlet to the entire surface of the molten metal. This is an exhaust duct.

Can be sprayed.

Therefore, the refining reaction of molten gold can be efficiently caused by the refining gas, and as a result, the refining time is significantly shortened and the amount of gas sucked is reduced compared to the conventional method.As a result, the amount of gold volatilization is drastically reduced, and high-purity gold is produced. of gold (99,999%).

In addition, as in the second invention, since the top of the melting crucible is covered with a cooling cylinder leading to the exhaust duct, the volatilized J during refining work is prevented.
The gold can be deposited as gold chloride on the inner wall of the cooling cylinder and recovered, which is economical, and there is no risk of the volatile gas components scattering in the workplace, which is preferable in terms of environmental hygiene.

Therefore, the intended purpose can be achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the apparatus of the present invention, and FIG. 2 is a sectional view showing a modification of the heating source. In the figure, (3) is a melting crucible, (4) is a gas blowing pipe, and (4) is a melting crucible.
') is the inlet, (A) is the molten gold, (b) is the purified gas, (
5) is a cooling cylinder, and (6) is patent applicant Tanaka Electronics Co., Ltd.

Claims (3)

[Claims] (1) In a device that purifies gold by blowing purified gas onto the surface of molten gold in a melting crucible through a gas blowing tube, an inverted funnel-shaped blowing port is provided at the tip of the gas blowing tube to create a gap on the surface of the molten gold. A gold refining device characterized in that the gold refining devices are arranged opposite to each other. (2) The refining device according to claim 1, wherein the gap between the inlet and the surface of the molten metal is adjustable. (3) In an apparatus for purifying gold by spraying purified gas through a gas blowing pipe onto the surface of molten gold in a melting crucible, an inverted funnel-shaped blowing port is provided at the end of the gas blowing pipe, and a gap is formed on the surface of the molten gold. A gold refining apparatus characterized in that the melting crucible is opposed to the melting crucible through a cooling cylinder which is connected to an exhaust duct.