Distribution & exploration of laterite-nickel ore resources
At present, explored nickel storage of the world is about 160 million tons, while 30% of this is sulfide ore and about 70% is laterite-nickel ore. Sulfide nickel and laterite-nickel is produced in the same ultramafic rock zone, but it is different from the copper ore deposit which has copper sulphide ore under the abundant cooper ore. As the quality of sulfide nickel resources is good and the process is mature, about 60% of nickel is produced from nickel sulphide ore, however as long-term exploration and no important breakup on the new resources exploration of sulfide nickel ore in recent 20 years, thus the storage decreased quickly. If calculated as 1,200,000tpa, means 2 year could finish exploration of one Canada Fuyixi Nickel ore deposit (only one large ore deposit discovered in recent 20 years which is 5th nickel sulfide ore in the world), 5 year could finish exploration of Jinchuan Nickel ore (3rd nickel sulfide ore in the world). Thus at present, worldwide sulfide nickel ore resources has shown the crisis, the exploration depth of traditional nickel ore has been gradually deepened and the exploration has been more difficult. In order for this, worldwide nickel industry has focused on the development of laterite-nickel ore resources.
Laterite nickel ore resources is located in tropical countries inside of 30 degree along the equators of the world and mainly distributes in the hot zones around Pacific Ocean - subtropical zone, mainly it is: Cuba, Brazil of America, Indonesia and Philippine in Southeast Asia, Australia, New Caledonia and Papua New Guinea, etc. of Oceania. 70% of our nickel resource is locates in Gansu, and then it distributes in Xinjiang, Yunnan, Jilin, Sichuan, Shanxi, Qinghai and Hubei Provinces, total storage is about 27% of national nickel resources. And main nickel ore type is cooper sulfide nickel ore and laterite-nickel ore. And laterite-nickel ore is mainly imported from Philippine. Since 1970 Japan and Philippine started cooperation and set up joint-venture of mining to explore high-level nickel ore with over 2% nickel which was transported to Ritie and Zhuyou for smelting, this caused the high0level nickel ore of Philippine monopolized by Japan, thus we can only imported low-level nickel ore with 0.9-1.1% nickel content.
The storage of nickel ore around our country is 11,250,000ton which only distributes in several countries including Russia (6,600,000ton), Indonesia (3,200,000ton), Philippine (410,000ton), Myanmar (920, 000ton) and Vietnam (120,000ton), however this storage has accounted for a large percent which is about 23%. Meanwhile laterite-nickel ore mainly distributes in Indonesia, Philippine and Myanmar. Nickel resources of Indonesia mainly laterite-nickel ore which is mainly distributes in east of group islands, mine zone could be searched in many areas, meanwhile as the laterite nickel ore widely distributes in Indonesia, the siegenite has better foreground. Philippine mainly is laterite-nickel ore which is mainly distributes in Nuonuoke Island. Myanmar has laterite silicic acid nickel ore which mainly distributes in western edge of middle basin. Nickel resources of Russia mainly distributes in Siberia area. Nickel ore of Vietnam is mainly koper-nikkel sulfide which mainly distributes in northwest.
Reasons for the development of worldwide laterial-nickel ore
Complying with the economic development in the nineties, the demand on stainless steel kept increasing which consumed 65% of nickel, in the last 5 years, average annual increase on nickel demand is over 4%, as forecasting, it will be 3.5-4% in following 5-10 years meanwhile the nickel demand in Asia will be 7%. However, the sulfided nickel resources which could be explored recently is very few except Voisey bay nickel ore in Canada. Total explored nickel resources is about 70 million tons in the world, including 30 million tons sulfided nickel which accounts for about 42%, and others are laterite-nickel ore. The advantages on developing to utilize laterite-nickel ores is:
1st, the storage of laterite-nickel ore resources is abundant, totally is about 41 million tons nickel in the world meanwhile its exploration cost is low.
2nd, exploration cost is very low.
3rd, Separating and smelting process has become mature. Pyrometallurgy of laterite-nickel ore technology has become mature; the thrust acid leaching technology is becoming mature gradually. This technology started in the fifties which were primarily used in Cuba Moa Bay mine which was called AMAX PAL Technology. After this, Australia ONI Company built Yabula nickel plant in the seventies utilizing acid leaching technology to treat laterite nickel ore. Canada Sherritt Company utilizing wet-process technology to treat laterite-nickel ore has been approved.
4th, laterite-nickel ore could produce nickel oxide, sulfided nickel and iron nickel, etc. intermediate product, while sulfided nickel and nickel oxide could be used for nickel refining plant which could solve the lack supply of sulfided nickel. Iron nickel could is good for manufacturing stainless steel and it could reduce the production cost. For example Indonesia Antam company utilized local laterite-nickel ore to produce iron nickel, the cost decreased to USD1.4/pound nickel last year (one pound is equal to 0.453kg) and the total output had about 10 thousand tons nickel content.
5th, worldwide laterite-nickel resources mainly distributes in the equator areas which is near to ocean and easy for transportation. Thus, the investment of laterite-nickel plant is large, normally each pound nickel needs USD9-11, but as the above mentioned advantages, if the process is reasonable, management is good, the production cost of each pound nickel could be lower than that of sulfided nickel. Take the largest nickel company WMC of Australia for example, total cost of each pound nickel (including amortization of investment) reduced from USD3.0 in 1996 to USD2.0 in 2000. Laterite-nickel ore with mature process and advanced management could reach this level. Especially the detailed feasibility report of thrust acid leaching technology for processing laterite-nickel ore in recent years has calculated the value of cobalt so the production cost of each pound nickel was less than USD1.4. Thus, the technology utilized by laterite-nickel developing center has changed into acid leaching from pytrometallurgy.
Complying with the setting up of three laterite-nickel plant in western part of Australia, people has new acknowledge of the performances and types of laterite-nickel resources, now it could be divided into two types: one is wet process which mainly distributes nearby equator such as Indonesia, Philippine and Caribbean, etc.; the other type is dry process which mainly distributes in the continent of southern hemisphere which is far away from equator and the representative is western Australia. Besides western Australia, laterite-nickel resources also distributes in eastern Australia which has gained 3 million tons nickel and the total amount of full Australia could reach 15 million tons nickel. Since 1999, 3 high pressure acid leaching nickel plant has started production in western Australia, they were Cawse, Bulong and Murrin Murrin, meanwhile they all took use of high pressure acide leaching technology, but the later process flow was different. Cawse produces intermediate product of nickel hydroxide then produce cathode nickel and sulfided cobalt. Bulong directly produces nickel and cobalt. Murrin Murrin is similar with Cuba Moy Bay Nickel Plant and takes use of the technology from Canada Sherritt, it produces mixed sulfided nickel and intermediate cobalt product, then produce nickel and cobalt.
A new group of PAL nickel plant construction and expanding project begin to be implemented and the developing trend is very obvious, this could come down to:
1st, as to be explored sulfided nickel resources is obviously reduced, the nickel output increasing in the following ten years of the world will mainly come from the development of laterite-nickel ore resources, however during the development of laterite-nickel ore resources, PAL technology developing trend is better than that of iron nickel technology;
2nd, the investment on PAL wet process technology and pytrometallurgy on laterite-nickel is almost the same which is about USD8-12 for each pound nickel. However, the investment on the expanding project of PAL technology nickel plant will obviously be reduced;
3rd, the production coast of PAL process is lower than that of iron nickel process under normal condition and the power consumption of PAL is lower than that of iron nickel. Thus PAL technology has obvious advantages in economy;
4th, as wet process laterite-nickel resources has high-level, less clay which is easy to treat and compared to the dry process laterite-nickel ore resources, the developing project of wet process resources has developing advantages.
5th, PAL technology of laterite-nickel ore could produce intermediate product: nickel hydroxide or sulfided nickel, thus this could solve the lack of raw material for refining nickel plant which is the developing direction of many nickel plant in western countries. And this is worth our learning.