Sumitomo Metal Mining Company, Ltd.

Shuuji Okada

Junichi Takahashi

Taku Inoue

Shintaro Ishikawa

Yoshihiro Okabe

Masamu Nishimoto

Akihiro Murakami

Kenya Ito

A smelting method capable of obtaining an iron-nickel alloy having a high nickel grade of 4% or higher by effectively facilitating a reduction reaction of pellets formed using a nickel oxide ore as a raw material. The present invention is a method for smelting a nickel oxide ore, by which an iron-nickel alloy is obtained by forming pellets from a nickel oxide ore and reducing and heating the pellets. In the pellet production step S, a mixture is obtained by mixing raw materials that contain at least a nickel oxide ore and a carbonaceous reducing agent. In the reduction step S, a furnace floor carbonaceous reducing agent is laid on the floor of the smelting furnace in advance when placing the obtained pellets in the smelting furnace and the pellets are placed on the furnace floor carbonaceous reducing agent and then reduced and heated.

Method for smelting nickel oxide ore

Provided is a method for producing a pellet capable of suppressing heat shock-induced crack occurrence, when nickel oxide ores are made into pellets and placed in a reducing furnace in a smelting process. In the method for producing a pellet from a nickel oxide ore, a nickel oxide ore, a binder and a carbonaceous reducing agent are mixed, the mixture is made into a lump, and then the resulting lump is subjected to a preheat treatment at a temperature of 350&#xb0; C. to 600&#xb0; C. In this preheat treatment, the lump more preferably undergoes the preheat treatment at a temperature of 400&#xb0; C. to 550&#xb0; C.

Method for producing pellet and method for smelting nickel oxide ore

Provided is a smelting method whereby a reaction for reducing pellets, said pellet being formed by using a saprolite ore as a starting material, can be effectively conducted and thus an iron/nickel alloy having a nickel grade of, for example, 16% or greater can be obtained. The method comprises: a pellet production step (S) for producing the pellets from the saprolite ore; and a reduction step (S) for heating and reducing the obtained pellets in a smelting furnace. In the pellet production step (S), at least the saprolite ore and a preset amount of a carbonaceous reducing agent are mixed together to produce the pellets. In the reduction step (S), a hearth carbonaceous reducing agent is preliminarily spread on the hearth of the smelting furnace and the pellets produced above are placed on the hearth carbonaceous reducing agent and then subjected to a heat reduction treatment.

Method for smelting saprolite ore

Provided is a smelting method capable of effectively promoting a reduction reaction on pellets formed using nickel oxide ore as starting material to obtain a ferronickel alloy with a high nickel grade of at least 4%. The present invention is a method for smelting nickel oxide ore wherein ferronickel alloy with a nickel grade of at least 4%, the method comprising a pellet-producing step Sfor producing pellets from nickel oxide ore, and a reducing step Sfor reduction-heating of the obtained pellets in a smelting furnace. In the pellet-producing step S, the pellets are produced by mixing nickel oxide ore with a specified amount of a carbonaceous reducing agent as starting materials. In the reducing step S, the produced pellets are charged in a smelting furnace in which a carbonaceous reducing agent (furnace bottom carbonaceous reducing agent) has been spread over the entire furnace bottom and reduction-heating is performed.

Provided is a method for smelting nickel oxide ore by which the occurrence of cracking due to heat shock can be suppressed when nickel oxide ore is pelletized and charged into a smelting step (reduction step). A method for smelting nickel oxide ore according to the present invention uses pellets of nickel oxide ore, the method being characterized by comprising a pellet production step Sfor producing pellets from nickel oxide ore, and a reduction step Sfor heating the resulting pellets at a predetermined reduction temperature in a reduction furnace, the reduction step Scomprising preheating the pellets obtained in the pellet production step Sto a temperature of 350 to 600&#xb0; C. in the reduction furnace and thereafter charging the pellets into the reduction furnace and raising the temperature of the reduction furnace to the reduction temperature.

The present invention provides a method for producing a silver powder, the method being capable of producing a silver powder with high productivity and at low cost, the silver powder having an average particle diameter of 0.3 to 2.0 &#x3bc;m and a narrow particle size distribution, and provides a silver powder produced by the production method. According to the present invention, the method for producing a silver powder includes: quantitatively and continuously supplying each of a silver solution containing a silver complex and a reductant solution to a flow path; and quantitatively and continuously reducing a silver complex in a reaction solution obtained by mixing the silver solution with the reductant solution in the flow path, wherein the reaction solution is made to contain a dispersant, and also a silver concentration in the reaction solution is adjusted to be in a range of 5 to 75 g/L.

Silver powder and method for producing same

Provided is a production method for producing pellets that are used for producing an iron-nickel alloy and that are produced by mixing at least a nickel oxide ore, a carbonaceous reducing agent, and an iron oxide and agglomerating the obtained mixtures, the method comprising: a step Sfor producing at least two types of mixtures having different mixing ratios of nickel oxide ore, carbonaceous reducing agent, and iron oxide; and a step Sfor forming pellets, which are agglomerates having a layered structure, by using the two or more types of mixtures such that the mixture with the highest content ratio of iron oxide, among the two or more types of mixtures forms the outermost layer.

Method for producing pellets and method for producing iron-nickel alloy

Provided is a method for producing pellets by which, when nickel oxide ore is being pelletized and smelted to produce ferronickel, which is an iron-nickel alloy, it is possible to allow the smelting reaction to proceed effectively. A method for producing pellets according to the present invention is for producing pellets which are used in producing iron-nickel alloy and which are produced by mixing raw materials including nickel oxide ore and agglomerating the resulting mixture, wherein the method comprises: a mixing step Sfor mixing at least nickel oxide ore, a carbonaceous reducing agent, and iron oxide to generate a mixture; and a pellet formation step Sfor agglomerating the resulting mixture and forming pellets. In the mixing step S, the mixture is generated such that the total weight of nickel and iron accounts for 30 wt % or more of the total weight of the pellets formed.

A method for smelting a nickel oxide ore, wherein the reduction step progresses effectively while maintaining the strength of the pellets, comprises: a pellet production step Sfor producing pellets from a nickel oxide ore; and a reduction step Sfor reducing and heating the obtained pellets in a smelting furnace at a predetermined reduction temperature. In the pellet production step Sa mixture is formed by mixing materials including said nickel oxide ore without mixing a carbonaceous reducing agent, and the pellets are formed by agglomerating said mixture. In the reduction step Sin charging the obtained pellets into the smelting furnace, a carbonaceous reducing agent is spread in advance over the furnace floor of the smelting furnace and the pellets are placed on the carbonaceous reducing agent, and the pellets are reduced and heated in a state where the pellets are covered by the carbonaceous reducing agent.

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Tokyo, Japan

Shuuji Okada