Cobalt Consumption in Carbide Industry

Carbide is sintered metal product using micrometer-sized powder of carbide of high-hardness refractory metals (tungsten carbide and titanium carbide) as main component and cobalt or nickel and molybdenum as binders. It is manufactured through sintering in vacuum oven and hydrogen reducing furnace. Matrix of carbide consists of two parts: one is hardening phase, whose content and grain size decide hardness of carbide, i.e. the higher content of hardening phase and finer grain size, the higher hardness; the other part is binders. Generally the iron group metal, commonly cobalt and nickel. Binders decide the toughness of carbide, i.e. the higher content of binders, the bigger bending strength.

Schroeter, a scientist in Germany, added 10%~20% cobalt to tungsten carbide powder in 1923 as binder, thus inventing new alloy of tungsten carbide and cobalt, whose hardness is just second to diamond. This was the first carbide made by man in the world.

Carbide is featured by excellent properties including high hardness, high strength, good toughness, good abradability, heat resistance and anti-corrosion. It is widely used as cutting tool materials like lathe tools, milling cutter, planer tool, drill and boring cutter. These tools are used for cutting cast iron, non-ferrous metal, plastics, chemical fiber, graphite, glass, stone and normal steel, as well as difficult-to-process materials like heat resistant steel, stainless steel, high manganese steel and tool steel. In addition, carbide can also be used in the making of rock drilling tools, digging tools, drilling tools, measuring tools, wear component, metal abrasive tools, lining of cylinder, precision bearing and nozzle.

1. Carbide is the second biggest field for cobalt consumption

In 2019, the globe consumed refined cobalt of about 134000 tons, where battery accounted for 62.46%, high temperature alloy accounted for 13.41%, carbide and diamond tools accounted for 5.81%, catalyst accounted for 4.30%, ceramics accounted for 4.00%, hard-surface materials accounted for 2.90%, tire and drier accounted for 2.80%, magnetic materials accounted for 2.20% and others accounted for 2.10%.

China’s cobalt consumption structure is different from that around the world. In our country, carbide industry ranks the second in cobalt consumption structure, which is mainly because carbide yield in our country ranks the first in the world. In 2019, cobalt consumption in China was about 69000 tons, where battery accounted for 81.6%, carbide accounted for 5.6%, high temperature alloy accounted for 2.9%, magnetic materials accounted for 2.6%, catalyst accounted for 2.6% and others accounted for 4.7% (see figure 2). From 2010 to 2019, although carbide-consumed cobalt volume decreased due to the fast growth of battery-consumed cobalt volume, the number always retains its second place on the list.

2. Cobalt powder is the principal raw material for the production of carbide

Cobalt powder is the principal raw material for the production of carbide. In carbide production, cobalt content generally accounts for over 99.8% and its grain size is between 0.5 micrometers - 4.5 micrometers.

Carbide sets high requirements for the purity of cobalt powder: on one hand, high-purity cobalt can be fully infiltrated in tungsten carbide and its high controlling can help to enhance the strength of carbide; on the other hand, any substance in cobalt powder like lead, silicon, calcium and sulphur will impact microstructure and performance of the carbide during its sintering. The production of carbide further involves mixing, pressing and sintering, where mechanical flow, plastic flow and thermal diffusion phenomenon will occur. Researches show that increased contact of SiC phase grains (due to reducing grain size of tungsten carbide) can be eliminated through highly uniform distribution that is realized by mechanical mixing and plastic flow of spherical cobalt powder with evenly distributed grain size, so that we can have carbide that is with higher hardness and toughness.

As carbide industry develops, the requirement for raw material cobalt powder is getting higher and higher. We bring up higher requirements not only for chemical component but also for physical properties like grain size, grain distribution and appearance of crystal.

3. Brief introduction of major international cobalt manufacturers

(1) Belgium Umicore Group

Belgium Umicore Group is the biggest cobalt powder manufacturer in the world. In addition to its research base and plant in Belgium, Umicore Group also owns cobalt powder companies in Fort Saskatchewan of Canada and Shanghai of China. It further invested to build Jiangxi Ganzhou Yihao Umicore Co., Ltd.. Shanghai Bailuoda Metal Co., Ltd. (China) is the holding subsidiary of Umicore in China. Bailuoda manufactures cobalt powder, a small part of which is sold in domestic market and a big part of which is exported to European and American market. Ganzhou Yihao Umicore Co., Ltd. manufactures cobalt oxalate for Shanghai Bailuoda Metal Co., Ltd. to manufacture cobalt powder.

(2) Shenzhen GEM Co., Ltd.

GEM Co., Ltd., a listed company on small and medium enterprise board in Shenzhen Stock Exchange, is mainly engaged in the recycling of “city mineral” such as waste battery, scrap electronic appliance, scrap cars and waste rare metals like cobalt, nickel and tungsten and research and industrialization of renewable goods. In 2019 in carbide industry, the company contributed sales volume of over 4700 tons of metal cobalt through its super fine cobalt powder (including cobalt carbonate), presenting a YOY growth of 18.43% and ranking the first place in global carbide market for 5 consecutive years. Its super cobalt powder occupies over 50% in domestic cobalt powder and over 40% in global cobalt powder market.

(3) Nanjing Hanrui Cobalt Co., Ltd.

Hanrui Cobalt Co., Ltd. is a listed company on growth enterprise board in Shenzhen Stock Exchange. It accounts for 30% in domestic cobalt powder and 20% in global cobalt powder market. In 2019, the company’s 3000-ton cobalt powder capacity in Chuzhou of Anhui went into operation, increasing capacity from 1500 tons to 4500 tons, achieving double growth and further consolidating leading position of the company in cobalt powder. The company has entered into stable cooperation with quality domestic and overseas customers including Korea Taegutec, Germany Betek, Japan Toshiba, Israel ISCAR, Germany E6, IMC (Dalian), CB-CERATIZIT Group, Zigong Carbide, Xiamen Tungsten.

4. Forecast for cobalt powder consumption in carbide industry of China

Tungsten-cobalt carbide mainly consists of WC and Co. License letters are YG (first letters of Chinese characters “硬” and “鈷”). License number means the average percentage of cobalt, like YG8 meaning average percentage of cobalt is 8%.

License number can range from 3% to 30%, dividing into high cobalt (20%~30%), medium cobalt (10%~15%) and low cobalt (3%~8%). 80% of carbide contains cobalt of 10%-12%, and it is estimated that average cobalt content of carbide is about 8%-10%.

In 2019, the yield of carbide globally was 108700 tons, and we can estimate that the consumption of cobalt powder was about 10800 tons.

Our carbide industry enjoys a robust development momentum for a long period of time. Industrial yield has been showing steady growth for 10 years, thus mobilizing steady growth in cobalt powder market. So far, China manufactures carbide of 30000-40000 tons annually so based on estimation, demand for cobalt powder is about 3000-4000 tons.

Carbide technologies develop and market competition intensifies, which leads to great growth in demand for high-end carbide products. In particular, superfine carbide becomes very popular relying on its high hardness and high strengths. Superfine carbide sets very high requirements for cobalt powder. The carbide made of superfine cobalt powder is much more outstanding than ordinary cobalt powder carbide in performance. We can say that, with the fast growth of superfine carbide, the demand for quality superfine cobalt powder will also increase significantly.

In 2019, the yield of carbide in China was about 36500 tons. The average annual growth over the past 9 years was 6%. According to estimation, by 2025, the yield of carbide in our country is likely to exceed 50000 tons. The average cobalt content in carbide is 8%-10%, which means that the demand for cobalt then will be 4000-5000 tons.

5. The tendency of cobalt replacement in carbide production

Krupp Corp of Germany started to industrialize the production of carbide in 1926, since when cobalt powder has been the best binder for the preparation of carbide. But its scarcity and high price have forced global carbide industry to develop low-cobalt and de-cobalt carbide. But little attention has been paid and little progress has been made. People have tried to replace cobalt with iron and nickel (the 8th family on periodic table of elements), but they ended up with no big breakthrough.

In February, 2019, scientists in CCDC Army Research Laboratory brought up that using iron-nickel-zirconium to replace cobalt as binder and adopting additive manufacturing to manufacture carbide. In October, 2020, United States Department of Defense allocated USD 2.45 million for Desktop Metal to conduct a three-year research of mass production of de-cobalt carbide and printing parts. It is suggested that domestic companies and scientific research institutions pay more attention to this new technology that might change the future of this industry.

The crucial point for our current carbide manufacturers is the recycling of waste carbide. From 2016 to 2018, cobalt price climbed greatly and a number of companies started to collect waste to improve recycling. In 2018 when cobalt price was at a high level, waste cobalt even accounted for as high as 70% in raw material source for some big plants.

Although average cobalt content in carbide is less than 10%, its influence to raw material cost of carbide is, however, over 20%, because the price of cobalt is much higher than tungsten. For this reason, our carbide companies should pay more attention to the variation of cobalt resource market. They need to well control the pace of market and adopt futures market and hedging to prevent big fluctuation of cobalt price. In the meantime, they need to increase investment in the research of new types of carbide that contain less cobalt or no cobalt.