Permanent Stainless Steel Cathodes

- Jul 17, 2018-

China  has  become  a  major  player in the international copper  market,  accounting  for  around 40

percent of global refined copper demand. Despite the slowdown  of the Chinese economy, the consumption

of copper products will still increase, but with a medium and/or low growth which will be the new situation

for the coming years. The average growth rate is expected to be around 5 percent per annual. In the coming

Five-Year plan  for  National  Economic and  Social Development  a number  of initiatives  will  be  finalized

which will require massive amounts  of copper. In 2015, the expected consumption of copper products will

be  over  9  million  metric  tons.  The main  driver of  the  consumption  is  the electric  power  industry which

accounts  nearly  the  half  of  the  total  consumption;  followed  by  cooling  application  with  15%  and

transportation with nearly 10%, see figure 1.

With  the  large  demand  of  copper  products  and  limited  resources,  China  imports  significant

quantities of copper  ores and waste/scrap for smelting and refining into  pure  forms of copper as well  as

refined copper products every year. At the same time, China’s copper smelting capacity has grown rapidly

over the last 20  years. The production of refined copper is expected to be over seven million metric tons in

2015. Today, many smelting and refining plants have been expanded and built.

As for the rest of the world, the pyrometallugy is the dominated technology for copper smelting in

China. The  electrolytic  refining  process  of copper has  actually  long  history  in  china, going back to  Ming

dynasty  (1587 –  1666). The  hydrometallurgical process of copper starts, however, relatively late in China.

The first real production using leaching (L) - solvent extraction (SX) - electrowinning (EW) process started

in 1983 in Hainan province. Today, the capacity of hydrometallurgy technology is still relatively small, just

about 200,000  metric tons.  However, due  to the  limited copper ore resources and grade of  copper ore, the

hydrometallurgical  process is  now  becoming more popular in China. It  is expected that the  L – SX –  EW

process will develop rapidly in the coming years.

With  both  electrowinning  (EW)  and  electrorefining  (ER)  processes  together,  20  large  scaled

copper  refineries  have  a  capacity  over  1.5  million  metric  tons  of  refined  copper  in  China.  A  rough

calculation indicates  that the demand for  cathode  plates will  be  200,000 to 300,000  pieces.  One new and

modern copper refining plant with a capacity of  100,000 metric tons alone will need about 22,000 cathode

plates. More similar projects will be carried out in the coming years, indicating there is a strong demand for

permanent cathode plates in China.

Since the introduction of permanent  stainless steel cathode  plates into the  copper refining process

in 1979 (Perry, 1980, 1983),  many techniques had been developed and introduced into the market (Bartsch

et  al.,  1987, Assenmacher,  1996).  Today,  the  permanent  stainless  steel  cathode  plate  has  been  widely

accepted and used in many large scaled copper refineries worldwide.

The  first  permanent  stainless steel  cathode  plates  were  introduced into  China  when  refinery  of

Jiangxi  Copper  Corporation  expanded  its  capacity  in  2002.  The cathode  plate  was  ISA  type  permanent

cathode and it was the first time being used in a large scaled refined copper production in China. Since then,

the KIDD type permanent cathodes were introduced by Jiangxi Copper Corporation and Jinlong Copper in

2007. The Outotec type permanent cathode was introduced into China by Shandong Xiangguang Copper in

2007. Today, all types of permanent cathodes are widely used in Chinese copper and other metal refineries.

Since the first permanent stainless steel cathode plates were introduced into China in 2002, local fabricators

have been established  and developed permanent stainless steel cathode production. They have  gained a lot

of experiences in  cathode  plate  technology, design, manufacture and  maintenance  since  2002. They  have

been grown rapidly along with the development of the Chinese refined copper industry.