Analyzing China"s Heavy Rare Earth Element Reserves (Part 1): Ion-absorbed Clays & Illegal Mining
Posted on October 5, 2012 by Karima Shajani
Hongpo* writes: This piece is part one of a two part series. Part I focuses on understanding China"s ion-absorbed-type rare earth deposits — that I think is the best and dominant rare earth mineral in the world. In Part II, I will explain further why China will not become a net importer of rare earth elements.
Various experts have said that China will be a net importer of rare earth elements (REEs), especially for heavy rare earth elements (HREEs)
For example:
"By 2014 or 2015, China will probably be in a net import situation for certain rare earths." — Mark Smith, CEO of Molycorp Inc (Source)
"China will become a net importer because its consumption for its own domestic value-added industry is going to drive very high [demand] growth for these resources. They"ve explored every inch of China for what"s available and if they had more rare earths deposits of any size, it would be being developed now." — Nicholas Curtis, CEO of Lynas Corporation Ltd. (Source)
"China can"t just turn on the tap, especially for HREEs. China is already having difficulty finding HREEs. Given time, China will likely become a net importer of the heavy and rare REEs." — Jon Hykawy, Brian Sylvester (Source)
"It is too early to make the assertion that China will be a net importer of all rare earth elements by 2015, but for heavy rare earth elements, it will coming soon." — Chen Zhanheng, PhD, Director of Academic Department, The Chinese Society of Rare Earths (Source)
I am very surprised that these views have not been questioned further or outright refuted. In my view, they could be wrong. I believe that China will not become a net importer of rare earth elements, be it light rare earth elements (LREEs) or HREEs, no matter what the year – be it 2015 or 2020 or beyond. In this piece, I build on my last piece titled, Analyzing China"s Light Rare Earth Element Reserves, by focusing on China"s HREE reserves.
What is an ion-absorbed-type rare earth deposit?
Constantine Karayannopoulos, CEO of Neo Material Technologies Inc. has said: "There is a reason why the rare earths are called rare. They"re not called rare because they"re truly rare. They"re called rare because it"s very difficult to isolate these elements individually and it takes a lot of skill to do that." (Source)
I think the ion-absorbed-type rare earth deposits, should in fact be called rare, because they have unparalleled heavy rare earth oxide (HREO) grades that can be derived from a very basic leaching method. Ion-absorbed-type rare earth deposits yield each of the 17 rare earth elements and they can be processed using relatively small operations and still be efficient — it"s simple, inexpensive and represents a faster mining process.
The picture to the left shows ion-absorbed-type rare earth minerals found in China – the white, gray, red, yellow loose sand clay, called ion-absorbed-type rare earth raw ore, also called weathering crust of rare earth ore leaching plot. It is rich in rare-earth minerals and soil, granite and volcanic mineral weathering. The formation of clay minerals is caused by the dissociation of hydrated ions of rare-earth ion hydration or hydroxyl ion adsorption in the clay minerals.
In ion-absorbed-type rare earth deposits, the rare earth elements are absorbed in the soil in the form of ions and most of these deposits are located in remote, mountainous areas. In China, there are so many of these mines scattered over a large area that are mining ion-absorbed rare earth minerals. These mines cover 17 regions of six Provinces in southern areas of China. All of 17 rare earth elements can be found in each and every ion-absorbed-type mine, according to proportion of total rare earth oxide (REO) content. The following chart shows the several areas and types of ion adsorption clays deposits of southern China:
How to mine the ion-absorbed-type rare earth deposits:
In mining ion-absorbed-type rare earth deposits, the leaching process is mechanically simple. In China, the utilization of in-situ leach mining creates less environmental damage than other methods used for mining ion-absorbed-type rare earth deposits. In addition, this mining technique is time-efficient and also more cost-effective. In the past, the outdated tank leaching and heap leaching techniques were employed at ion-absorption middle and heavy rare earth mines, creating 2,000 tonnes of tailings for each tonne of rare earth oxide (REO) produced, causing severe damage to surface vegetation, soil erosion, pollution, and acidification, and reduced or even eliminated food crop output.
This in-situ leach mining method is a variation on heap leaching and can offer recovery rates of around 75%, with no blasting or significant land excavations. Once the source has been identified, the rare earths are extracted by drilling thousands of shallow holes, one to two meters in diameter, at the top of the mountain into which ammonium carbonate solution is then distributed via PVC pipes, using taps to control the flow. Thousands of holes, three to four inches in diameter, are then drilled into the side of the incline to leach out the REO-bearing discharge.
It takes around 25-30 days for the leaching process to take effect and the solution to dissolve the REOs. The REO liquid is collected at the bottom of the incline and transferred to a nearby production facility where it will begin the filtering process. Further ammonium sulphate solution is added at this point which begins the precipitation process and enables the removal of natural waste. This process takes around eight hours to take effect.
Stronger ammonium sulphate solution is then added to force the separation of the REO from the liquid. Once the concentrate has settled in the holding pools it is then removed and allowed to dry. The drying process will usually take one to two weeks depending on weather conditions. The concentrate is then pressure dried using a standard pressing machine.
A Chinese ion-absorbed-type rare earth mining enterprise has provided me with the leaching process flow chart that follows:
Why is illegal mining difficult to regulate in China?
"One cannot make an omelet without breaking eggs." A simple mining method makes it easy to extract the rare earths but it also makes it difficult to regulate. Also, most of the southern ion-absorption rare earth deposits are located in remote mountainous areas, with many mines scattered over a large area making it difficult and costly to monitor mining operations. As a result, illegal mining has severely depleted local resources, and mines rich in reserves that are easy to exploit are often favored over the others, resulting in a low recovery rate of the rare earth resources.
Illegal mining is very easy because people only need tractors and shovels. Then using the tank leaching and heap leaching method they can extract rare earths with ammonium sulfate. This can be done easily, even by those without extensive training. Cases of illegal mining have not only been found in Jiangxi, Ganzhou, but also in adjacent Guangdong, Guangxi and and Fujian provinces, where illegal mining is rampant, where officials and local villagers also take a share of the profit. The cost of illegal mining is low, the lowest price is 20,000 Yuan to 30,000 Yuan per tonne, including the money used for bribes that account for a significant portion of total costs. The salary paid to employees is also low, at about 300 Yuan per person per day. Illegal miners hire employees to exploit rare earths at night, and they work from 7pm to 7am.
The resources are taken for free and no heed is paid to the environment. Covert exploitation of rare earths is more rampant than drug dealing because you can make the same profits in this business as smuggling drugs, but the risks are much lower. Drug dealers in China can face a death penalty, but people involved in illegal mining of rare earths are only sentenced to seven years in prison at most, according to the law. In the past few years, industry consolidation has been a major theme within the Chinese rare earth sector. Although China has taken comprehensive measures in the links of mining, production and exporting of rare earth goods and strengthened efforts for the protection of the resource and the environment. Illegal mining remains prominent and is still a major source of production for rare earth materials and is expected to still account for as much as 40-50% (40,000-50,000 tonnes) of total current supply.
Illegal mining and smuggling of the ion-absorbed-type rare earth deposits greatly damages the environment, but it has not been prevented because it will yields super high profits. Unfortunately, illegal mining of rare earths also effects China"s heavy rare earth element reserves because most of the illegally mined REEs are smuggled to the rest of the world. However this is being addressed and consolidation within the Chinese domestic rare earth industry and the continued battle on illegal production will enable China to further tighten its stranglehold on the production of heavy rare earths.
*Disclaimer: While we have a full name for Hongpo, we have never met him in person. We made some minor grammatical changes to the text he submitted and edited some of the content on a best-case effort towards capturing the editor"s intent.
This entry was posted in Rare Earth Intel and tagged China, Heavy Rare Earth Elements by Karima Shajani. Bookmark the permalink. |
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