Mineral resources and metals

Metal trading

London Metal Exchange (LME)

The LME specializes in trading of non-ferrous metals such as copper, nickel, aluminum, lead and zinc.
The LME trading prices for metals are used as the international pricing benchmarks for sales of refined metal and purchases of refining ores.


Treatment Charge (TC) and Refining Charge (RC) are common- ly used in the terms of purchase for copper concentrate or nickel ore for refining.
They are amounts designed to cover refining costs. For example, copper concentrate contracts may define a purchase price based on the LME price at a certain date, minus the TC or RC being used at the time.

London fixing

Gold is not traded on the LME.
Its price is determined for each transaction between market participants.
The financial institutions in the London Bullion Market Association (LBMA) agree a standard price for gold based on these transactions and publish it on the morning and afternoon of each trading day. This "London fixing" price is the benchmark for trading in gold.

Pound (lb)

Part of the imperial system of measures, the pound is the stan- dard unit of weight used in measuring and pricing base metals such as copper and nickel, and in TC/RC calculations.
One pound is equal to 453.59 grams; an imperial ton equals 2,204.62lb.

Troy ounce (toz)

The troy ounce is the standard unit of weight for precious metals such as gold and silver. It equals approximately 31.1 grams. It is named after Troyes, a city in the Champagne region of central France that was the site of a major market in Europe in medieval times. Originally used as a unit of exchange for valuing goods in terms of gold or silver weights, the troy ounce is still used today in gold trading.

Metal refining

Smelting and refining

Refining processes extract valuable metals from ores or other raw materials.
They fall into two basic types: pyrometallurgical (dry) and hydrometallurgical (wet). At SMM’s Toyo facilities in Ehime Prefecture, the copper concentrate pre-processing undertaken at Saijo uses pyrometallurgical processes and the nickel refining at the Niihama site uses hydrometallurgical processes entirely.
The term "smelting" is used for the extraction of metal from ores using melting and heating (pyrometallurgy). The term ‘refining’ refers to any process that increases the grade or purity of a metal.

Pyrometallurgical refining

The precursor ore is melted at high temperature in a furnace, and refining techniques are applied to separate the metal in a molten state.

Hydrometallurgical refining

The ore and impurities are dissolved in a solution, and chemical reactions are used to separate out the metal.

Metal ores

Sulfide ores

These ores contain copper, nickel or other metals chemically bonded to sulfur.
Since the application of heat breaks these bonds, releasing the sulfur, such ores are generally refined using pyrometallurgical techniques.

Oxide ores

These ores contain metals in oxidized forms.
Unlike sulfide ores, oxides need much more energy to achieve melting. For this reason, the hydrometallurgical approach is generally used to refine these ores.

Copper concentrates

Used as raw materials in copper smelting, copper concentrates have a copper content of about 30% by weight. The remainder consists mostly of sulfur and iron. Copper concentrates are made mostly from sulfide ores.
Ores extracted from overseas mines have a typical grade of about 1%. The ores are then "dressed" at the mine to increase the purity and produce concentrate. Most of the copper ores imported by SMM for smelting in Japan are concentrates.

Nickel oxide ores

Whilst the higher-grade sulfide ores are used predominantly in nickel refining, nickel oxide ores are more prevalent than nickel sulfides. The sulfide-oxide ratio in current nickel reserves is believed to be about 3:7.
High refining costs and technical issues have limited use of oxide ores in nickel refining to date, but SMM has succeeded in refining nickel from low-grade oxide ores based on HPAL technology.

Mixed sulfide (MS)

CBNC and THPAL produce a mixed nickel-cobalt sulfide intermediate containing about 60% nickel by weight. This is used as a raw material in nickel related production such as electrolytic nickel.


A matte is another term for metal sulfides.
For raw material, nickel related production such as electrolytic nickel at SMM also uses a nickel matte (of about 75–80% purity) sourced from PT Vale Indonesia.

Proprietary ore ratio

This ratio is the proportion by volume of ore procured from overseas mining interests relative to the overall volume of smelting ores used as raw materials.
Typically, off-take rights are proportional to the equity interest in a mine.
In the case of Cerro Verde, SMM has secured 50% off-take rights for the first ten years of production from 2006, based on a 21% equity interest.

Nickel production process

Coral Bay Nickel Corporation (CBNC)

Based in the Philippines, this SMM subsidiary produces mixed nickel-cobalt sulfides (MS) using HPAL technology and exports the raw materials to the SMM Group’s nickel refining facilities at Niihama Nickel Refinery and Harima Refinery.

Taganito HPAL Nickel Corporation (THPAL)

Based in the Philippines, this SMM subsidiary produces mixed nickel-cobalt sulfides (MS) using HPAL technology and exports the raw materials to the SMM Group’s nickel refining facilities at Niihama Nickel Refinery and Harima Refinery.

High Pressure Acid Leach (HPAL)

HPAL technology enables the recovery of nickel from nickel oxide ores that traditionally were difficult to process.
SMM was the first company in the world to apply it successfully on a commercial scale.
The oxide ores are subjected to high temperature and pressure and reacted under stable conditions with sulfuric acid to produce a nickel-rich refining intermediate.

Matte Chlorine Leach Electrowinning (MCLE)

MCLE is the technology used in the manufacturing process at SMM's nickel refinery.
The matte and mixed sulfide ores are dissolved in chlorine to produce high-grade nickel using electrolysis. MCLE is competitive in cost terms, but poses significant operational challenges.

Main applications for metals

Main applications for copper

Copper is fabricated into wires, pipes and other forms.
Besides power cables, copper is used widely in consumer applications such as wiring in vehicles or houses, and in air conditioning systems.

Main applications for electrolytic nickel

This form of nickel, which has a purity of at least 99.99%, is used in specialty steels, electronics materials and electroplating, among other applications.
SMM is the only producer of electrolytic nickel in Japan.

Main applications for ferronickel

Ferronickel is an alloy containing nickel (about 20%) and iron. Its main use is in the manufacture of stainless steel, which is about 10% nickel by weight. Based in Hyuga, Miyazaki Prefecture, SMM Group firm Hyuga Smelting produces ferronickel.

Main applications for gold

Gold is in demand worldwide for investment and decorative purposes.
Gold is widely used in industry within the electronics sector because of its high malleability and ductility. Part of SMM's gold production goes to SMM Group companies engaged in fabricating and selling bonding wire.

Electronics and advanced materials

Copper-clad polyimide film (CCPF)

CCPF is a polyimide film that is coated using a copper base.
It is used as a material for making COF substrates.
SMM commands a top share of the CCPF supplied for use in large liquid crystal displays.

Secondary batteries

Secondary batteries are ones that can be recharged and used again.
SMM supplies battery materials that are used in the anodes of nickel metal hydride batteries and lithium-ion rechargeable batteries, which supply power for hybrid vehicles or notebook computers, among other consumer applications.

Unit conversion table

toz g kg
1 31.1 0.0311
0.0321 1 0.001
32.15 1000 1
lb g kg
1 454 0.454
0.0022 1 0.001
2.205 1000 1