Nickel, a silver-white metal, was first isolated in 1751 by A.F. Cronstedt, a mineralogist of Sweden. It is a quite important nonferrous metal raw material owing to its good mechanical strength and ductility, refratoriness, high chemical stability, and unoxidizability in air. It is used for stainless steel, high-Ni alloy steel and alloy constructional steel as well as for airplanes, radar, guided missiles, tanks, warships, space shuttles, atomic reactors and other military manufacturing industries. In civil applications, nickel is utilized in large quantities for constructional steel, acid-resistant steel, refractory steel and other manufacturing industries. In addition, nickel can be used in ceramic paints and corrosion-resistant plating; nickel-cobalt alloy is a permanent-magnet material which is widely applied to electronic remote control, atomic energy, supersonic technology and other fields. Nickel is also often used as a catalyst of hydrogenation in chemical industry. In recent years, the consumption of nickel in such respects as color TV sets, tape recorders and communication equipment has been increasing rapidly. In general, the good properties of nickel have made it an indispensable metal in developing modern aircraft industry and national defence industry and in establishing a modern system of high-level material and cultural life of man.    

3.10.1 Resources

3.10.1.1Reserves and Resources   

As of the end of 1997, China had explored 83 nickel districts, which are distributed in 18 provinces or autonomous regions of the country, and owned a total retained nickel reserve of 7.7710 million tons, of which categories A+B+C (3.6992 million tons) accounts for 47.6% of the total. If the industrial reserve (i.e. categories A+B+C) of China is comparable with the reserve base of the Western countries, the country would rank 9th in the world, after Cuba (with the reserve base of 23.00 million tons), New Caledonia (15.00 million tons), Canada (14.00 million tons), Indonesia (13.00 million tons), the Philippines (11.00 million tons), Russia (7.30 million tons), Australia (6.80 million tons) and Brazil (4.30 million tons). In the 1960s, due to the successful exploration of the Jinchuan Cu-Ni sulfide deposit in Gansu, the nickel reserve of China was more than doubled within 10 years. Since 1975, its ratained nickel reserve has basically been stabilized at 7.60~7.80 million tons.   

Nickel resources in China are relatively abundant, predicted at about 9.00 million tons. The most promising areas are the Huangshan area of Hami, the Qiongtage area and the northern margin of the Tarim Basin, all in Xinjiang.   

3.10.1.2 Characteristics   

China's nickel resources are regionally distributed chiefly in the northwest, southwest and northeast of the country, which hold 76.8%, 12.1% and 4.9%, respectively, of the country's total retained reserve. Among its provinces or autonomous regions, Gansu has most abundant nickel reserve (accounting for 62% of the country's total), next coming Xinjiang (11.6%), Yunnan (8.9%), Jilin (4.4%), Hubei (3.4%) and Sichuan (3.3%).   

Fig. 3.10.1 shows the distribution of major nickel deposits in China, and Table 3.10.1 presents the state of development of these deposits. The most important are: the Baijiazuizi Cu-Ni deposit, the Hongqiling nickel deposit, the Baimazhai nickel deposit, the Dapoling Cu-Ni deposit and the Mojiang nickel deposit.

The Baijiazuizi deposit, also called the Jinchuan Cu-Ni deposit, is a superlarge one located within Jinchang City, Gansu Province. It was discovered in 1958, and the reconnaissance survey began in 1959, followed by prospecting. The final prospecting report on ore district III of it was submitted in 1966, that on ore district II was completed in 1972, and the preliminary prospecting of ore district IV was concluded in 1973. The cumulative explored reserve of copper obtained from the deposit is 3.5044 million tons, and that of nickel 5.5365 million tons. Grades of the deposit are: 0.47%~1.64% nickel and 0.24%~1.66% copper. The deposit is also an important source of platinum group and cobalt metals of China.

Construction of the mine started in 1960. In 1965, the 1st ore-dressing plant and an open-pit mine were successively put into production; in 1966, the nickel-electrolyzing workshop of a smelter of the 10,000-ton size, belonging to the first-phase project, came into operation; and during the 8th Five Year Plan the second-phase project for expansion was completed. As a result, an annual productive capacity of 40,000 tons of nickel and 20,000 tons of copper was established.   

The Hongqiling nickel deposit is a large one, of which the ore district is administratively under Hongqiling Town, Panshi County, Jilin Province. No. 1 ore-bearing rock body of the deposit was found in 1958. In 1964, the then Ministry of Metallurgical Industry launched a mass campaign of geological prospecting in the Hongqiling ore district, resulting in the identification of No. 7 ore-bearing rock body. This is the predominant rock body in the district, which has 204,400 tons of cumulative explored nickel reserve averaging 2.30% Ni in grade.

Table 3.10.1 China's major nickel deposits and their state of development

Besides nickel, it contains 39,000 tons of copper (the copper ore grade being 0.63%) and a certain amount of cobalt and celenium. In 1960, small-scale mining of the No. 1 ore-bearing rock body was carried out; in 1964, the corresponding mine was  constructed and went into operation; and in 1971, a large open-pit mine built on the No. 7 ore-bearing rock body was put into production.   

The Baimazhai nickel deposit lies northwest of the town of Jinping County, Yunnan Province. It was discovered in 1957 and formally prospected in 1960, and the report on its reserve was submitted in 1965. This is a medium-sized nickel deposit with a retained nickel reserve of 53,200 tons and a grade of 1.23% Ni.    

The Dapoling nickel deposit, located 32 km northwest of Luocheng County, Guangxi, has a cumulative explored reserve of 13,200 tons of nickel and over 6,800 tons of copper. Its average grade of nickel is 0.55% and that of copper, 0.28%.   

The Mojiang nickel deposit, located at the border between Yuanjiang and Mojiang countries, Yunnan, consists of 6 ore zones (or segments). It was discovered in 1957 and prospected in 1958. The prospecting report was submitted at the end of 1959. It is a large deposit with a total explored nickel reserve of 531,300 tons and the grades of 0.86%~0.91% Ni.   

All of the known major nickel deposits in China are of the magmatic liquation type, except the Mojiang deposit in Yunnan that is of the weathered crust type. The magmatic liquation nickel deposits are geotectonically distributed mostly in paraplatform internal, transitional and geosynclinal internal areas. Nickel deposits in the transitional area (i.e., a zone between the paraplatform and the geosyncline) are predominant, with the remaining being subordinate (Table 3.10.2).

Table 3.10.2 Distribution and metallogenic ages of major nickel deposits in China

In the transitional area which is located at the junction of different geotectonic units, deep fault zones are extremely well-developed. These far-extending large-scale zones generally have a long history of activity and are major factors controlling the rock- and ore-forming processes of nickel deposits. Such a control effect is manifested primarily by the following: 1) discontinuous distribution of the rock bodies and suites along the deep fault zones; 2) emplacement of the rock bodies generally along the hanging wall of the  zones; 3) due to the earlier formation time and long multicyclic development of the zones, there are generally outcrops of 2 or even more generations of rock bodies in the terrain on one side of a deep fault; and 4) the rock zones or suites on one side of a deep fault all occur in the second-order faults or folds at the hanging wall of the deep fault.   

Besides geotectonic factors, ultramafic-mafic rock bodies also play an important role in controlling the distribution of nickel deposits. The rock type, size, attitude and differentiation degree of such a rock body are intimately related to the mineralization of nickel: 1) Among the numerous rock bodies in the rock zones or suites, very few can form a nickel deposit. The 14 rock zones (suites) have a total of 2,038 rock bodies, of which only 28 have formed nickel deposits, with the mineralization rate being only 1.37%. This indicates that in a rock zone (suite), the mineralization is related only to a certain generation of rock bodies with a favorable rock type. 2) The nickel-mineralizing rock bodies are usually small in size. Of the mineralizing rock bodies, only three (Baijiazuizi, Chibaisong and Dapoling) have an outcrop area of 1 km2, and the rest are all below 0.1 km2 in area. 3) According to the strike and dip, the mineralizing rock bodies can be classed into two types: one is steeply dipping (over 60¡ã) and dyke-like, vein-like or lenticular in shape; the other is gently dipping sill, lopoliths, and is ellipsoidal and flat-columnar in shape. Gigantic and large deposits occur in the form of the first type. And 4) the degree of differentiation of rock body is closely related to the mineralization: generally a higher degree of differentiation is more favorable for the mineralization.   

Nickel deposits in China may range in time from the Precambrian to the Yanshanian, with the Proterozoic and the Hercynian being the two main mineralization epochs. Deposits formed in the Proterozoic are the Chibaisong, the Baijiazuizi and the Dapoling, of which the isotope ages are 2,240 Ma, 1,509~1,526 Ma and 1,000~1,100 Ma, respectively. Those formed in the Sinian are the Lengshuiqing and Jianchaling deposits which have isotope ages of 713 Ma and 518~590 Ma, respectively. There is only one deposit (Lashuixia) that was formed in the Caledonian. Deposits formed in the Hercynian are many: the early Hercynian deposits are represented by the Hongqiling deposit, while the late Hercynian ones, by the Baimazhai deposit. The Mojiang weathered crust nickel silicate deposit belongs to the Indosinian-Yanshanian.   

As for the characteristics of nickel resources in China, firstly,the reserves are highly concentrated in distribution. The Jinchuan nickel deposit in Gansu alone constitutes 63.9% of the country's total nickel reserves. The three Cu-Ni deposits (Kalatongke, Huangshan and East Huangshan) in Xinjiang account for a combined 12.2% of the country's total retained reserves.   

Secondly, China's nickel deposits are mostly Cu-Ni sulfide ones that make up 86% of the country's total retained reserves. Next come lateritic nickel deposits that amount to 9.6% of the country's total retained reserves.   

Thirdly, nickel ores in China are relatively high in grade, and the rich nickel sulfide ores averaging over 1% Ni in grade account for about 44.1% of the country's total retained reserves.    

Fourthly, the degree of geological work on the nickel deposits of China is comparatively high: the reserve of prospecting class forms 74% of the country's total retained reserves.   

Fifthly, the nickel deposits in China suitable for underground mining occupy a higher percentage(68%) of the country's total retained reserves, while those suitable for open-pit mining make up only 13%.   

The above characteristics of nickel resources in China not only create favorable conditions for but have unfavorable influences on the development and utilization of the resources. The concentrative distribution of the ore reserves and the relatively high grades of the ores make it easy to establish large enterprises for ore mining, dressing and smelting and obtain better economic efficiency. For instance, in the Jinchuan ore province in Gansu that has large reserves and high grades of ores, there are 48,400 tons of extremely rich ore rereserves (grading 5.29% Ni) and more than 10 metals such as the platinum group, gold and cobalt in its ore district II. Now a flowsteet for multipurpose utilization of the ores is in operation there, and the district has become the largest nickel-producing base in China. It should be noted, however, that the high concentration of the reserves and deep burial of the ores (impossible for open-pit mining) make it difficult to expand the production and enhance the economic efficiency.    

Nickel oxide ores in China are few in quantity and low in grade, less competitive than those (of large reserves and high grade) in such countries as New Caledonia and Indonesia.