ANALYSIS ON THE MARKET DEVELOPING CONDITIONS OF PREBAKED CARBON 

ANODES FOR THE ALUMINIUM INDUSTRIES

Guanghui Lang, Chunyu Fu, Ronald Logan,Yan Li

Sunstone Development Ltd, Beijing 100029, China

Keywords: Prebaked Carbon Anode, Large-Scale Production, Aluminium Industry

Abstract

In recent years, with the sustained and rapid development 

of the aluminium electrolytic industries worldwide, an 

unprecedented growth of Chinese prebaked carbon anode 

production has been achieved. The high-quality and abundant 

sources of raw materials for anode production, unique 

production technologies, experienced operators, governmental

support of research, and efficient logistics have made the further 

development of large-scale and integrated anode production 

facilities possible. China is positioned to become the production 

base of prebaked carbon anodes for the electrolytic business all 

over the world in the future. 

Introduction

The prebaked carbon anode industry in China has been 

booming in recent years with the rapid development of 

domestic and overseas aluminium industry. And China has 

become the largest producer and exporter of prebaked carbon 

anodes in the world. The production of prebaked carbon anodes

can not only meet the domestic demand but also worldwide. 

And the prebaked carbon anodes, as kind of international trade 

product, have been exported more and more from 1999. Fig. 1 

shows the anode export volume from 1999 to 2009. We could 

see the increase is extremely large in 2008 and 2009, of which 

volume increased over 70%. 

Fig. 1 Chinese anode export volume(kt)

from 1999 to 2009

Raw Materials

China has the largest number of independent prebaked 

carbon anode manufactures, which makes China the largest 

anode producer and exporter in the world. This is mainly due to 

the raw material advantages China has.

Today, China has become the world’s largest producer and 

supplier of Green Petroleum Coke (GPC) and Coal Tar Pitch 

(CTP), which are the two main raw materials of making 

prebaked carbon anodes. And the raw materials’ cost covers over 

65% in the anode cost. So the raw materials are very important 

for prebaked carbon anode production. 

GPC

The output of GPC has been increasing in the past few years 

due to the expanded capacity of coking units and the increased

downstream demand in China. The GPC used as fuel is about 

7,300kt last year, which is the highest demand in the history. In 

addition, the GPC used for making anodes is undoubly the 

largest percentage. We could see from Fig. 2 that the apparent 

consumption of GPC is higher than the domestic output for the 

first time in 2009. 

Fig. 2 The output and apparent consumption of GPC 

in China during 2004 to 2009 (www.ChinaCCM.com)

The prebaked carbon anodes used for aluminium smelters is 

mainly produced by low and middle sulfur GPC[1]. The annual 

output of low and middle sulfur GPC in China has been 

increasing year by year, which is shown in Fig. 3. Same trend is 

observed for the percentage of low and middle sulfur GPC, 

which is shown in Fig. 4 (The increase slows down in 2008 due 

to the economy crisis worldwide). In 2009, the GPC output 

increased by over 1,000kt compared to 2008, while the low and 

middle sulfur GPC percentage increased from 66% to 68%,

mainly due to Huizhou Refinery Plant of China National 

Offshore Oil Corporation with a capacity of 4,200kt and other 

five local oil refineries with a capacity of 5,000kt putting into

operation.

Chi nese GPC 2004 – 2009 ( kt )

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

2004y 2005y 2006y 2007y 2008y 2009y

pr oduct i on appar ent consumpt i on
Fig. 3 The output of Low and Middle Sulfur Coke in China 

from 2007 to 2009 (www.ChinaCCM.com)

Fig. 4 The percentage of Low and Middle Sulfur Coke in 

China from 2007 to 2009 

The domestic GPC can not only meet the market demand but 

also has better quality than overseas, Table 1 shows the quality 

differences of both domestic and overseas GPC.

Table 1 Specification Comparison of GPC Produced 

in China and Overseas

Remark: V+Ni no more than 550ppm for coke produced outside of 

China

As raw materials for anodes,GPC has the advantages of 

low ash, low sulfur, low moisture, high heat, low impurity and 

low volatile matter. In 2009, there was about 54% of GPC used 

for making prebaked carbon anodes (Fig. 5 shows the green coke 

consumption proportions in China in 2009). 

Fig. 5 Green Coke Consumption Proportions

in China in 2009

CTP

According to the investigation by Koppers (Fig. 6), we can 

learn that the global increase of coal tar is mainly due to the 

increase in China during 2004 to 2012. In 2010, the total deepprocessing capacity of coal tar is about 13,000kt in China. About 

14 deep-processing enterprises with over 300kt capacity and 10 

new projects with over 150kt capacity. While in 2009, the total 

output is about 4,000kt (Fig. 7), in which 32% of the coal tar 

consumption is for making prebaked carbon anodes (Fig. 8)[3]. 

Fig. 6 Global Tar Availability during 2004-2012[2]

Fig. 7 Coal Tar Pitch output in China from 2007 to 2009 

(www.ChinaCCM.com)

Fig. 8 Coal Tar Consumption in China in 2009

SPECS UNIT CHINA OVERSEAS

Ash % 0.3MAX 0.5MAX

VOM % 8-12MAX 8-14MAX

Moisture % 0.3MAX ---

Shot Coke % 0 0-5%

Sulphur % 1.5-2.5MAX 2.0-3.5MAX

Vanadium PPM 200MAX 350MAX

 Nickle PPM 200MAX 200MAX

 Iron PPM 200MAX 200-400MAX

 Silicon PPM 200MAX 150-350MAX

 Calsium PPM 250MAX 200MAX

 Sodium PPM 150MAX 200MAX

 

car bon f or

f uel , 29% al umi ni um , 54%

si l i con met al ,

7%

ot her s, 10%

Chinese Low and Mid Sulfur as Percentage of total GPC

Production (kt)

12500

13000

13500

14000

14500

15000

15500

16000

16500

17000

2007 2008 2009

China GPC Production

64.50%

65.00%

65.50%

66.00%

66.50%

67.00%

67.50%

68.00%

68.50%

Low and Mid Sulfur as

Percentage of total GPC

Production

Chi nese Low and Mi d Sul f ur GPC Pr oduct i on ( kt )

0

2000

4000

6000

8000

10000

12000

2007y 2008y 2009y

Chi na Pet r ochemi cal Cor p. Gr oup Chi na Nat i onal Pet r ol eum Cor p.

Chi na Nat i onal Of f shor e Oi l Cor por at i on Local Oi l Ref i ner i se
The Quality of Prebaked Carbon Anodes

Anode manufacturers should have strict QC system to 

guarantee the quality compliance of their final products during 

the whole production process because it is a mass production 

process. The quality of prebaked carbon anodes in China has 

been improved greatly by the technical exchanges with 

international advanced partners constantly during the past ten 

years. Chinese prebaked carbon anodes can not only be used in 

large amperage electrolytic cells but also large current density

ones. The gap of quality with the developed countries is getting 

smaller and smaller. And the property variations, which was not 

paying much attention to in the past, has become one of the most 

important index to all manufacturers. 

Good quality prebaked carbon anodes can not only reduce 

the carbon emissions in the downstream industry but also cut the 

production cost of downstream aluminium smelters. For instance, 

it can save about 40 to 80 RMB per tonne of aluminium cost if 

the net consumption of carbon reduced by 10 to 20kg per tonne 

of aluminium. For a 500kt aluminium smelter, it could save 20 to 

40 million RMB a year. Considering the 13,000kt of aluminium 

output in 2009, it could save 520 to 1,040 million RMB. 

At the present time, there is a certain gap of quality

requirements for anodes between domestic and overseas

aluminium smelters because the domestic smelters are not strict 

about the quality of prebaked carbon anodes. For example, most 

of the Chinese aluminium smelters require only one parameter, 

that is electrical resistivity, while the overseas smelters have 10 

to 18 parameters need to be tested. If the anode specifications are 

not reasonable enough, it is very likely to increase the production 

cost and decrease the metal quality of smelters. Cost-wise, anode 

cost is about 10% to 15% of the total aluminium cost, some even 

higher, so to some extent the anode property has a great impact 

on aluminium cost. More importantly, nowadays, large smelters 

worldwide are trying to increase the size or current density of the 

electrolytic cells to cut the cost, which consequently will require 

anodes to have even better quality to be running in these pots. So 

it’s becoming more and more critical to improve the anode 

quality. 

Advantage of large-scale production 

The large-scale production of prebaked carbon anodes can 

avoid the loss of raw materials and reduce the environment 

pollution during transport. 

Comparison between transported raw materials and 

transported anodes as below:

As the liquid CTP has the characters of no water and no 

melting, 40% of exported CTP is of liquid form in 2009. But it is 

very difficult to transport and store considering the 

environmental issues. 

Comparison between transported raw materials and 

transported anodes as below:

The environmental protection treatment system costs not 

only the investment of the system itself, but also funds that keep 

put into it to keep it functioning efficiently. This would lead to 

an increase to the unit cost of the anodes. By large-scale 

production, we could manage to reduce the unit cost. For 

example, the RTO technology can settle the problem of

benzoylene pollution ultimately. But at present, the investment is 

too high to popularize it all around the world. Only some anode 

plants in Europe uses this technology. And it is predicted that it 

will get popularized in the near future as every country will 

invest more to protect the environment. At present, the domestic 

anodes plants can meet the environmental standards completely. 

Here take Sunstone as an example. The index is shown in Table 

2.

Table 2 Polluting emissiosn from carbon plant

Workshop Pollution Emission 

mg/Nm3

National 

standard 

mg/Nm3

Baking

Fluoride 0-8 9

Coal tar 5-20 40

SO2 3-80 550

Dust 10-90 120

Calciner

SO2 100-120 550

Dust 60-90 120

Green mill

Coal tar 10 40

Dust 20 120

The large-scale production can also make the further

investment on R&D possible and realize the recycling economy

along with the changes of the abroad customers and the market.

Conclusions

We can learn that the supply of GPC and CTP for large-scale 

production in China is guaranteed. The large-scale production 

can put a great deal of investment into R&D and improve the 

quality of prebaked carbon anodes. The gap of quality between 

the developed and developing countries can also be reduced in 

order to meet the demand of the international market. It can be 

proved by the increased export quantity of prebaked carbon 
anodes. Under the large-scale production, it can be more 

economical and environmental friendly by transporting anodes

instead of raw materials through the efficient transportation 

system. At the same time, these positive factors can promote 

Chinese prebaked carbon anode industry into a large-scale 

production. It may become an active circle in the whole chain.

References

1. Xinjian Zhang, Shiwen Zhang. “The Carbon for Aluminium 

Industry and the production technology”(2001)

2. Robert H. Wombles, “Pitch Market Dynamics: impact of 

high growth / high Amperage Demand Curve” (Black China

Conference, 2008)

3. Zhenhui Huang, “The Chinese market of Coal Tar Pitch in 

2010” (The conference of Coal Tar Pitch industry, 2010)