JPH0913127A - Method for recovering gold from gold-containing material and device therefor - Google Patents

Abstract

PURPOSE: To provide a method of recovering gold from a gold containing material such as a metal plating, a metal lining, a gold-containing ore by adding a metal reducing agent such as iron into an aq. solution, in which gold is eluted as a thiourea compound. CONSTITUTION: Gold is recovered by dipping the gold-containing material <=2g/l in an eluting aq. solution containing 1.5-5.0% ferric ion and 2.0-6.0% thiourea and after stirring and vibrating, adding a metallic body having equal to or above solid-liquid contact area than 2g/l (above aq. solution for elution) powdery metal such as the iron powder as the reducing agent and stirring and vibrating. The metallic body 2 is a thin plate rotating body and provided in the eluting solution so as to be rotatably dipped. As a result, the treating time is reduced to 1/12 to 1/24 of that by a method using a cyan compound and 2/3 of that by a pH adjusting method using an alkali to reduce the treating cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for recovering gold from gold-containing products such as gold-plated products, gold-plated products, ores containing gold (hereinafter referred to as gold-containing products). .

[0002]

2. Description of the Related Art Hitherto, as a method for recovering gold from a gold-containing material, a method using aqua regia or a method using a cyanide compound has been used. As is well known, aqua regia is a mixture of nitric acid and hydrochloric acid, which is extremely dangerous to handle, and the cyanide compound is a toxic substance. However, from the aspect of environmental protection, there has been a strong demand for improvement. To meet this demand, for example, there is a proposal according to Japanese Patent Laid-Open No. 60-103138.

In this proposal, 0.5 g / l of iron ion was added as an oxidizing agent to an aqueous leaching solution containing 3 g / l of thiourea as a leaching agent of gold and silver from ores, and 1 g of an alkaline agent was added thereto. Add specified sodium hydroxide to adjust pH to 6.5
After the above, or after aeration at a rate of 0.8 l / min for 30 minutes, an alkaline agent is added to coprecipitate gold and silver during the precipitation of iron hydroxide produced with a pH of 4.0 or higher. Is to separate gold and silver.

[0004] This proposal is
Gold ore from an ore containing silver, an aqueous solution in which silver is leached as a thiourea compound, zinc powder as a reducing agent, hydrazine,
When gold and silver were recovered using sodium sulfite and the like, it was found that the amount of the reducing agent used became large and the practicality was significantly reduced, and an experiment was conducted to improve this.
It was found that when an alkaline agent is added to the leaching aqueous solution of gold and silver described above in the presence of iron ions to adjust the pH, gold and silver are co-precipitated with the generated iron hydroxide to achieve the purpose,
This is the requirement of the means.

However, as in this proposal, an iron ion having no reducing ability is present in an aqueous solution containing a thiourea compound of gold or silver in an amount of about 10 to 100 times that of gold, and alkali is directly added to the aqueous solution, or the emulsion is used. After that, by adding an alkali to increase the pH of the above aqueous solution and producing iron hydroxide, and coprecipitating gold and silver in the leaching aqueous solution together with the produced iron hydroxide, the amount of the coprecipitate is large. In addition, the property becomes a gel-like slurry form. The work of drying this and recovering the gold is extremely difficult, the efficiency of the processing work deteriorates,
The reality is that we cannot expect improvement in practicality.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and provides a safe method.
Short processing time. Good workability. Cheap cost. It is an object of the present invention to provide a method and apparatus for recovering gold from a gold-containing material.

[0007]

In order to achieve the above-mentioned object, the inventors of the present invention have proposed a reduction treatment with zinc powder, which is a basis for giving up the reduction treatment with a metal in JP-A-60-103138. As a result of an additional experiment, zinc powder of 10 g / l- (leaching aqueous solution) or more is required, and about 100 g of lead, which is a similar metal, is required. If 25 g / l of lead is used, the treatment time is 24 hours. It was found that the above-mentioned abandonment was grounded.

However, as a result of further experimentation, when the following metals were used as a reducing agent in the form of a powder or a linear body, the required amount was significantly different, and iron was 2 g / l- (leaching Aqueous solution), tin 2g / l- (leaching solution), nickel 2g / l
-(Leached solution), Cadmium 5g / l- (Leached solution), Copper 5g / l- (Leached solution), Aluminum 5g
/ L- (leaching aqueous solution), it is significantly reduced, and in using these, there is no difference in effect even if any one kind or a mixture of two or more kinds is used. It has been found that it takes only about 2 hours until the gold is leached and then the gold is recovered from the gold leaching aqueous solution.

The present invention has been made on the basis of these findings. In an leaching aqueous solution containing 1.5 to 5.0% by weight of ferric ion and 2.0 to 6.0% by weight of thiourea, the amount of gold was
A gold-containing material of 2 g / l- (leaching aqueous solution) or less is immersed, and the leaching aqueous solution is stirred and / or vibrated for 60 minutes or more, and then a metal such as iron, tin, nickel, cadmium, copper or aluminum is added to the leaching aqueous solution. The solid-liquid contact area of the metal is 2 g / l of metal powder.
-The first means is a method of adding or immersing the leaching aqueous solution in an amount equal to or larger than the solid-liquid contact area, and collecting gold from the gold-containing material that stirs and / or vibrates the leaching aqueous solution for 15 minutes or more,

Iron, tin, nickel, cadmium,
A plurality of circular metal plates containing metals such as copper and aluminum are fixed through the shaft to form a metal body, and a part of the circular metal plate of the metal body is immersed in a gold leaching aqueous solution and is rotatable. The second means is an apparatus for recovering gold from the gold-containing substance provided in the container for the gold leaching aqueous solution.

An important requirement in the present invention is the solid-liquid contact area of the metal in contact with the gold leaching aqueous solution. In the present invention, the contact area of the metal and the gold leaching aqueous solution is equal to or more than the metal powder 2 g / l- (leaching aqueous solution). It is limited to the solid-liquid contact area.

Usually, the shape of the metal powder is often a plate having a thickness of about 0.05 mm, and the specific gravity of the above-mentioned metal ranges from about 2.7 of aluminum to about 8.9 of copper. The solid-liquid contact area equivalent to 2 g / l- (leaching aqueous solution) has a lower limit of about 45 cm ² / l- (leaching aqueous solution) calculated from powdered copper.

In order to always secure this contact area, the influence of fluctuations in the amount of the leaching aqueous solution is small, and the contact area can be adjusted from the number of revolutions. For example, iron is used as the metal of the metal body and the iron is rotated. When the iron body composed of the thin iron plate group is used as shown in FIGS. 7 and 8, the workability of gold recovery work, processing efficiency, and processing cost are further improved.

The metal body composed of this rotating thin metal plate group may be installed so as to be rotatable together with the container containing the gold leaching aqueous solution as shown in FIGS. 7 and 8 or fixedly installed. It may be installed in the container of the gold leaching solution so that the metal body can rotate.

[0015]

In the present invention, since the above means is used, the work is safe and the leaching time is 1/12 to 1/24 as compared with the method using a cyan compound which requires 24 to 48 hours. Compared with the method proposed by Japanese Patent Laid-Open No. 60-103138, which requires 3 hours, it is 2/3 as short as the method.

Further, the recovery of gold from the leaching aqueous solution is not accompanied by the coprecipitation phenomenon with iron hydroxide, so the amount of the processed product is greatly reduced, and the physical properties of the processed product are dry. As a result of being able to use dry refining with good recovery efficiency and recovery work efficiency,
The workability is remarkably improved, the processing cost is drastically reduced, the leaching rate of gold from the gold-containing material reaches 90% or more, and the gold recovery rate from the gold leaching aqueous solution can easily reach 99% or more. R.

[0017]

EXAMPLES The present inventors repeated various experimental studies in order to achieve the above object. Hereinafter, an experimental study example that obtains the results of FIGS. 1 to 6 will be described. This example has a diameter of 370 mm
, A body length of 420 mm, a PVC container with a content of 18 liters, length 7 cm 1 width 1
A sample of 1 cm and a gold plating amount of 32.9 g / kg- (weight of gold content) was stored, and a leaching aqueous solution containing ferric ion added in the form of thiourea and sulfate was injected into the sample, and the vinyl chloride container was used. Is rotated with a ball mill at a rotation speed of 100 to 110 rpm to stir and vibrate the leaching aqueous solution to obtain a gold leaching aqueous solution, and then iron powder is added to the gold leaching aqueous solution as a metal reducing agent, and the vinyl chloride container is further added. Is an example of collecting gold by stirring and vibrating the gold leaching aqueous solution by rotating the above method.

FIG. 1 shows the ferric ion content and gold leaching rate in the leaching aqueous solution, FIG. 2 shows the thiourea content and gold leaching rate in the same solution, and FIG. 3 shows the gold in the same solution. Fig. 4 shows the immersion amount of the inclusions and the leaching rate of gold, Fig. 4 shows the addition amount of the iron powder used as the metal powder to the same liquid, and the recovery rate of the gold, and Fig. 5 shows the results when the gold inclusions were immersed. The stirring and / or shaking time of the leaching aqueous solution and the gold leaching rate are shown, FIG. 6 shows the stirring and / or shaking time of the leaching aqueous solution to which the iron powder is added, and the gold recovery rate, and FIG. Instead, a usage example of the electrode plate-shaped circular thin iron plate is shown in plan view, and FIG. 8 is a plan view showing an overview of a usage example of the relative rotary wiper body for mechanically collecting gold from the surface of the electrode plate-shaped circular thin iron plate. Show.

As is apparent from FIGS. 1 to 6, the gold content in the leaching aqueous solution containing 1.5 to 5.0% by weight of ferric ion and 2.0 to 6.0% by weight of thiourea was 2.0 g / l or less. After immersing and stirring and / or vibrating for 60 minutes or more, the gold leaching rate of the gold-containing material reaches 90% or more, and 2 g / l- (leaching aqueous solution) or more iron powder is added to the gold leaching aqueous solution. It was found that the recovery rate reaches 99% or more after stirring and / or shaking for 15 minutes or more.

In the above example, iron powder was used as the reducing agent, but the present invention is not limited to iron powder, and a solid-liquid contact area equal to or larger than the solid-liquid contact area of iron powder 2 g / l- (leaching aqueous solution) is used. An iron body having, for example, an iron body 3 configured by installing a circular thin iron plate 2 formed in a battery electrode plate shape on a fixed shaft 1 as shown in FIG.
Was prepared, and was mounted and fixed in the vinyl chloride container 4 with a fixture 5 and rotated together with the container 4 to allow gold to be leached from the gold-containing material, and then the fixture 5 of the iron body 3 was removed to remove the iron. After the body 3 is taken out and the iron body 3 is fixed to the shaft fixing device 6, the whole surface of the thin iron plate 2 is clamped by the wiper 8 of the relative rotary wiper body 7 as shown in plan view in FIG. The rotary shaft 9 fixing the wiper 8 is driven by a rotary drive device 10 (Gard motor) to wipe the surface of the thin iron plate 2, and the obtained coprecipitate is subjected to dry refining to recover gold. You can also do things.

According to this method, the content of gold in the coprecipitate is higher than that in the above example, and the work can be carried out by automatic control or continuous control, which saves labor and improves workability and work efficiency. Therefore, the gold recovery cost is further reduced than the above example.

Further, the above-mentioned other metal bodies can also be constructed and used in the same manner as in the above example. Metals other than iron can be used by coating the surface of a thin iron plate with each metal by a known means such as plating, vapor deposition, bombardment, and sticking. Further, as the material of the wiper 8, a brush or knife made of synthetic resin or metal can be used without any trouble.

In the above, the gold-containing material is an example of a gold-plated product. However, in the same manner as in the above-mentioned example, an aqueous solution obtained by leaching gold from a gold-containing material such as a gold-plated product or a gold-containing ore is also used. It is possible to recover gold with the same effect through the same effect.

[0024]

INDUSTRIAL APPLICABILITY According to the present invention, the above-mentioned action can be exerted by using the above-mentioned means. Therefore, unlike the conventional method using aqua regia and the method using the cyanide compound, there is no danger, and the method is safe and simple. Gold can be recovered from gold-containing materials at a recovery rate as high as or higher than those. Further, as proposed in Japanese Patent Laid-Open No. 60-103138, since a recovery method of producing a large amount of iron hydroxide and coprecipitating gold with the iron hydroxide is not used, the product to be treated during the gold recovery work is not used. Since the amount is small and the processed material has a dry property that is easy to handle, the processing workability is remarkably improved, and the gold recovery cost is greatly reduced.

[Brief description of the drawings]

FIG. 1 shows the ferric ion content and the gold leaching rate of a leaching aqueous solution.

FIG. 2 shows the thiourea content and the gold leaching rate of the leaching aqueous solution.

FIG. 3 shows the amount of gold-containing material dipped in the leaching aqueous solution and the gold leaching rate.

FIG. 4 shows the amount of iron powder added to the leaching solution and the recovery rate of gold.

FIG. 5 shows the relationship between the leaching rate of gold and the stirring and / or vibration time of the leaching aqueous solution in which the gold-containing material was dipped.

FIG. 6 shows the stirring and / or vibration time of an aqueous gold leaching solution containing iron powder and the recovery rate of gold.

FIG. 7 is a plan view showing an example of use of an iron body formed of an electrode plate-shaped thin iron plate instead of iron powder.

FIG. 8 is a plan view showing an outline of an example of use of a relative rotary wiper that mechanically recovers gold from the surface of an iron body composed of an electrode plate-shaped thin iron plate.

[Explanation of symbols]

1: Fixed shaft 6: Shaft fixing device 2: Electrode thin iron plate 7: Relative rotation wiper body 3: Iron body 8: Wiper 4: PVC container 9: Rotation shaft 5: Fixture 10: Rotation drive device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Manabu Kitasaka 3239, Oita-shi, Oita-shi, Oita-city 3239-4 Oita Prefectural Industrial Testing Station (72) Inventor Katsuto Hiramatsu Oita-shi, Oita-shi, Oita-shi 3239-4 Oita (72) Inventor Tsukasa Sakahara 1-7-4 Akenominami, Oita City, Oita Prefecture

Claims (2)

[Claims] 1. A ferric ion of 1.5-5.0% by weight and 2.0-
A leaching aqueous solution containing 6.0% by weight of thiourea was dipped with a gold content of 2 g / l- (leaching aqueous solution) or less as the amount of gold, and after stirring and / or vibrating the leaching aqueous solution for 60 minutes or more,
A metal such as iron, tin, nickel, cadmium, copper or aluminum is added to the leaching aqueous solution so that the solid-liquid contact area of the metal is a metal powder.
A method for recovering gold from a gold-containing material characterized by adding or immersing 2 g / l- (leaching aqueous solution) in an amount equal to or more than a solid-liquid contact area and stirring and / or vibrating the leaching aqueous solution for 15 minutes or more. . 2. Iron, tin, nickel, cadmium,
A plurality of circular metal plates containing copper, aluminum, etc. are pierced and fixed to a shaft to form a metal body, and a part of the circular metal plate of the metal body is immersed and rotatable in an aqueous solution in which gold is leached. An apparatus for recovering gold from a gold-containing material, wherein the metal body is provided in a container for the gold leaching aqueous solution.