【発明の詳細な説明】[Detailed description of the invention]
〔産業上の利用分野〕
本発明は金、銀を含む硅酸鉱から、金、銀を収
率よく回収する方法に関するものである。
〔従来の技術〕
従来、金、銀をそれぞれ0.ng／Ton以上含む含
金銀硅酸鉱の製錬法としては、金、銀の回収のみ
を目的とした湿式法と、そのまゝ銅あるいは鉛の
乾式製錬の溶剤として使用し、金、銀を副産物と
して回収する乾式法がある。
湿式法としては、全泥青化法が広く実施されて
いるが、シアンを含む廃液及び尾鉱の処理が問題
となる。また、シアン液を使用しない湿式法とし
てはチオ尿素法、浮選法があるが、前者はまだ研
究段階で実用化はされておらず、（STUDIES
AND PROSPECTS OF GOLD
EXTRACTION FROM CARBON BEA−
RING CLAYEY GOLD ORE BY THE
THIOUREA PROCESS、CHEN DENG
WEN：PREPRINTS−THE CANADIAN
INSTITUTE OF MINING AND
METALLURGY， INTERNATIONAL
MINERAL PROCESSING CONGRESS，
TORONTO，CANADA，OCTOBER 17−23，
1982，−8.1〜−8.11）、後者は金、銀の収率
が約93％（金の実収率）と低い等の問題がある
（昭和56年度選鉱青化主要原単位成績表、日本鉱
業協会編）。
又、銅あるいは鉛製錬の溶剤として使用する方
法、例えば銅自溶炉および銅転炉において溶剤と
して使用する方法では、生成する〓のFe（％）／
SiO2（％）値は〓の物性値から限られており、自
溶炉〓では1.0前後、転炉〓では1.8〜2.0程度であ
り、これら以下の値になるまで更に硅酸鉱を溶解
しようとする〓の粘性及び融点が著しく上がり
（日本金属学会編「非鉄製錬」P.63，THE
METALLURGICAL SOCIETY OF CIM
ANNUAL VOLUME，P.156，1977参照）〓中
への銅損失が増大する。
この粘性及び融点の上昇に対処するためには、
溶体温度を上げざるを得ないが、耐火物の溶損が
激化し、実際上は困難となる。特に通常の転炉〓
ではFe3O4を25〜35％含み、このような組成では
SiO2の少量の増加によつて融点が著しく上昇し、
加えた硅酸鉱の一部が未溶解のまゝ残り、金、銀
の一次収率が低下する。
〔発明が解決しようとする問題点〕
本発明は、含金銀硅酸鉱を溶解し、金銀を収率
よく回収する新たな方法を提供し、銅製錬におけ
る含金銀硅酸鉱の処理能力を大幅に増大させるこ
とを目的とするものである。
〔問題点を解決するための手段〕
本発明はこの目的を達するために、銅転炉〓に
還元剤と含金硅酸鉱を加えて溶解し、回収される
銅分に金、銀を吸収させることにより含金銀硅酸
鉱を処理する方法である。
反応の機構は、溶融状態の銅転炉〓中に還元剤
を加えることにより〓中のFe3O4が還元され、〓
の粘性が低下し、懸垂していた銅分が沈降分離
し、また化学的に溶解していた酸化銅の一部も還
元され回収される。又、この還元反応を進行させ
ながら含金銀硅酸鉱を加えて溶解すると、含金銀
硅酸鉱の中の金、銀は沈降分離する銅分中に吸収
され、SiO2は〓中のFe3O4が還元されて生成した
FeOとフアイヤライトスラグを形成するものであ
る。こゝで、本発明においては、銅転炉〓に含金
銀硅酸鉱を加えつつ還元剤を加えるので、いわゆ
る銅転炉〓の還元によるスラグクリーニングの場
合よりもFe／SiO2の低い条件で還元するもので
あり、従つて生成する〓中のFeOの活量が低下す
るのでFe3O4はより還元しやすくなり、且つ高温
で起き易いFeにまで還元し過ぎる反応を抑える
働きをする。
還元剤の添加方法としては、羽口を有する治金
炉（例えば非鉄製錬用転炉）を用いて、羽口より
微粉炭と酸素富化空気を〓中に吹き込む方法、羽
口の代わりに上吹きランスを用いる方法、電気炉
あるいは熱補償用のバーナーを有する炉において
石炭等の還元剤を〓中に投入する方法、プロパン
等の還元性ガスを用いる方法などがある。
還元の進行あるいは硅酸鉱の添加により、〓温
度が低下するが、硅酸鉱を完全に溶解するには、
1200〜1300℃の温度を維持する必要があり、その
為には硅酸鉱の添加速度の制御、熱補償用補助バ
ーナーの使用、電気炉による場合にはその負荷の
制御、羽口から微粉炭および酸素富化空気を吹き
込む場合には吹き込み空気の酸素濃度及び温度の
制御が必要となる。
〓への金、銀の損失は、その殆んどが金、銀を
吸収した含銅粒子が機械的に〓中に懸垂する為な
ので、最終〓中のCu濃度、回収される銅分の金、
金濃度に影響される。
〓中のCu濃度は〓中のFe3O4濃度に影響され、
発明者等が〓処理量３〜4Ton／回のPS転炉で羽
口より微粉炭と空気を吹き込む方法により硅酸鉱
を最終〓中のFe／SiO2が約1.0になるまで溶解し
た結果（第１図参照）では、最終〓のCuを0.5重
量％程度まで下げるには最終〓のFe3O4が２重量
％以下であるのが望ましいことが判つた。
回収される銅分の金濃度と最終〓中の金濃度の
関係は、発明者等が前述の試験で金濃度の異なる
硅酸鉱を使い、回収銅分量を変化させた場合に、
第２図（図中で黒丸は最終〓中のCu≦0.5重量％
の場合であり、白丸は0.7〜１重量％の場合であ
る。）の様であり、最終〓の金濃度を0.1ｇ／Ton
以下にするには最終〓中のCu≦0.5重量％で、回
収銅分の金濃度が60ｇ／Ton以下とし、最終〓の
金濃度を0.2ｇ／Ton以下にするには最終〓中の
Cu≦0.5重量％で、回収銅分の金濃度が170ｇ／
Ton以下とするのが望ましいことが判る。又、
Agの挙動についても同様と推測される。従つて、
含金銀硅酸鉱中の金、銀濃度が高く、転炉〓中の
銅分だけでは回収銅分の金、銀濃度が高くなり過
ぎる場合には精製炉〓、銅滓などの含銅物を加え
回収銅分の金、銀濃度を低くするのが望ましい。
含金銀硅酸鉱は最終〓のFe／SiO2が0.8程度に
なるまで処理できる。そのサイズは細かな程溶解
速度が大きく有利であるが、20mm程度の塊であつ
ても1200〜1300℃で100〜150分程度の保持により
溶解可能である。その供給方法は塊状のものは炉
上からの投入方法、粉状のものは羽口もしくはラ
ンスから吹き込む方法で良い。
得られた最終〓はCu、Au、Agいずれも低下し
ており棄却可能であるが、回収銅分はまだFe等
不純物濃度が高いので通常の銅製錬の転炉工程等
で処理する必要がある。
〔実施例〕
実施例 １
レンガ内張りの内径1.5ｍ内長さ1.7ｍのPS型転
炉に表−１に示した組成の銅転炉〓３Tonを装入
し、内径21mmの羽口４本から平均風量15.1Nm3／
分、平均酸素濃度25.6容量％の酸素富化空気と圧
縮空気により流送される微粉炭4.6Kg／分を吹き
込みながら15〜20mmの塊状の表−１に示した組成
の含金銀硅酸鉱1.0Tonを炉口に差し込んだシユ
ートにより装入した。吹錬時間は150分であり、
前半90分の間に含金銀硅酸鉱を連続的に装入し
た。
最終〓の物量は3.5Tonで、回収銅分の物量は
0.15Tonであり、これらの組成も表−１に示し
た。
得られた回収銅分への金、銀回収率はそれぞれ
96重量％であつた。
[Industrial Application Field] The present invention relates to a method for recovering gold and silver in good yield from silicate ore containing gold and silver. [Conventional technology] Conventionally, the methods for smelting gold-bearing silver silicate ore containing more than 0.ng/Ton of gold and silver each include a wet method for the sole purpose of recovering gold and silver, and a wet method for the sole purpose of recovering gold and silver. There is a dry method in which lead is used as a solvent in pyro-smelting, and gold and silver are recovered as by-products. As a wet method, the total mud cyanization method is widely practiced, but the treatment of cyanide-containing waste liquid and tailings poses a problem. In addition, there are wet methods that do not use cyanide, such as the thiourea method and the flotation method, but the former is still in the research stage and has not been put into practical use (STUDIES
AND PROSPECTS OF GOLD
EXTRACTION FROM CARBON BEA−
RING CLAYEY GOLD ORE BY THE
THIOUREA PROCESS, CHEN DENG
WEN：PREPRINTS－THE CANADIAN
INSTITUTE OF MINING AND
METALLURGY, INTERNATIONAL
MINERAL PROCESSING CONGRESS
TORONTO, CANADA, OCTOBER 17-23,
1982, -8.1 to -8.11), and the latter has problems such as a low gold and silver yield of about 93% (actual gold yield) (1982, ore beneficiation blue major unit performance report, Japan Mining Association) (ed.). In addition, in the method of using it as a solvent in copper or lead smelting, for example, in the method of using it as a solvent in a copper flash furnace and a copper converter, the amount of Fe (%)/
The SiO 2 (%) value is limited due to the physical property value of 〓, which is around 1.0 in a flash furnace and around 1.8 to 2.0 in a converter, so try to melt the silicate ore further until the value is below these values. The viscosity and melting point of
METALLURGICAL SOCIETY OF CIM
(Refer to ANNUAL VOLUME, P.156, 1977) Copper loss to the inside increases. To deal with this increase in viscosity and melting point,
Although it is necessary to raise the solution temperature, the melting loss of the refractory becomes more severe, making it difficult in practice. Especially normal converter〓
contains 25-35% Fe 3 O 4 , and with such a composition
A small increase in SiO 2 significantly increases the melting point,
A portion of the added silicate ore remains undissolved, reducing the primary yield of gold and silver. [Problems to be Solved by the Invention] The present invention provides a new method for dissolving gold-containing silver silicate ore and recovering gold and silver with high yield, and greatly increases the processing capacity of gold-containing silver silicate ore in copper smelting. The purpose is to increase the number of people. [Means for Solving the Problems] In order to achieve this objective, the present invention adds a reducing agent and gold-containing silicate ore to a copper converter and melts it, and absorbs gold and silver into the recovered copper. This is a method for treating gold-containing silver silicate ore. The reaction mechanism is that by adding a reducing agent into the molten copper converter, Fe 3 O 4 in the copper converter is reduced, and
The viscosity of the copper oxide decreases, the suspended copper sediments and separates, and a portion of the chemically dissolved copper oxide is also reduced and recovered. Also, when gold-containing silver silicate ore is added and dissolved while this reduction reaction progresses, the gold and silver in the gold-containing silver silicate ore are absorbed into the copper content that settles and separates, and SiO 2 becomes Fe 3 in the O 4 was reduced and produced
It forms ferrite slag with FeO. Therefore, in the present invention, since the reducing agent is added while adding the gold-containing silver silicate ore to the copper converter, the Fe/SiO 2 content can be lowered than in the case of slag cleaning by reduction in the so-called copper converter. Since it is a reducing substance, the activity of FeO in the produced 〓 decreases, making Fe 3 O 4 easier to reduce, and also serves to suppress the reaction of excessive reduction to Fe, which tends to occur at high temperatures. The reducing agent can be added by using a metallurgical furnace with tuyeres (for example, a converter for nonferrous smelting) and blowing pulverized coal and oxygen-enriched air into the furnace through the tuyeres. Methods include using a top blowing lance, charging a reducing agent such as coal into the furnace in an electric furnace or a furnace equipped with a burner for heat compensation, and using a reducing gas such as propane. As the reduction progresses or the addition of silicate ore, the temperature decreases, but in order to completely dissolve the silicate ore,
It is necessary to maintain a temperature of 1200 to 1300℃, and for this purpose, it is necessary to control the addition rate of silicate ore, use an auxiliary burner for heat compensation, control the load if an electric furnace is used, and remove pulverized coal from the tuyere. When blowing oxygen-enriched air, it is necessary to control the oxygen concentration and temperature of the blown air. Most of the loss of gold and silver to 〓 is due to the mechanical suspension of copper-containing particles that have absorbed gold and silver, so the Cu concentration in the final 〓 and the gold content of recovered copper ,
Affected by gold concentration. The Cu concentration in 〓 is influenced by the Fe 3 O 4 concentration in 〓,
The inventors melted silicate ore by blowing pulverized coal and air through the tuyeres in a PS converter with a throughput of 3 to 4 tons/time until the Fe/SiO 2 content in the final solution reached approximately 1.0 ( (see Figure 1), it was found that in order to reduce the Cu content of the final product to about 0.5% by weight, it is desirable that the Fe 3 O 4 content of the final product be 2% by weight or less. The relationship between the gold concentration in the recovered copper and the gold concentration in the final solution was as follows when the inventors used silicate ores with different gold concentrations in the above-mentioned test and varied the amount of recovered copper.
Figure 2 (black circles in the figure indicate Cu≦0.5% by weight in the final
The white circles represent the cases of 0.7 to 1% by weight. ), and the final gold concentration is 0.1g/Ton.
To achieve the following, Cu≦0.5% by weight in the final product, and the gold concentration in the recovered copper content to be 60g/Ton or less, and to make the gold concentration in the final product 0.2g/Ton or less, the gold concentration in the final product must be 60g/Ton or less.
Cu≦0.5% by weight, gold concentration of recovered copper is 170g/
It can be seen that it is desirable to set it to less than ton. or,
It is assumed that the behavior of Ag is similar. Therefore,
If the concentration of gold and silver in the gold-containing silver silicate ore is high and the concentration of gold and silver in the recovered copper becomes too high if only the copper in the converter In addition, it is desirable to lower the gold and silver concentrations in the recovered copper. Gold-bearing silver silicate ore can be processed until the final Fe/SiO 2 ratio is about 0.8. The finer the size, the higher the dissolution rate, which is advantageous, but even a lump of about 20 mm can be dissolved by holding it at 1200 to 1300°C for about 100 to 150 minutes. As for the feeding method, if it is in the form of a lump, it may be introduced from the top of the furnace, or if it is in the form of powder, it may be blown in through the tuyere or lance. In the final product obtained, Cu, Au, and Ag have all decreased and can be rejected, but the recovered copper still has a high concentration of impurities such as Fe, so it needs to be treated in the converter process of normal copper smelting. . [Example] Example 1 A 3 ton copper converter with the composition shown in Table 1 was charged into a PS type converter with an inner diameter of 1.5 m and a length of 1.7 m, lined with bricks. Average air volume 15.1Nm 3 /
While blowing oxygen-enriched air with an average oxygen concentration of 25.6% by volume and 4.6 kg/min of pulverized coal conveyed by compressed air, the gold-bearing silver silicate ore 1.0 with the composition shown in Table 1 is produced in the form of 15-20 mm blocks. Ton was charged through a chute inserted into the furnace mouth. The blowing time is 150 minutes,
Gold-containing silver silicate ore was continuously charged during the first 90 minutes. The final amount was 3.5 tons, and the amount of recovered copper was
0.15Ton, and their compositions are also shown in Table-1. The gold and silver recovery rates for the recovered copper content are respectively
It was 96% by weight.
【表】【table】