Rare Earth Metals Mining and Processing: Like Wringing Blood form Stone?

Given the technical challenges faced by start up rare earth metals miners and producers even since Mainland China lowered the quota they want to sell to the world market, is getting rare earths from the ground really like wringing blood from stone?


By: Ringo Bones


When the People’s Republic of China decided to lower the quota of rare earth metals that it sells to the world market in order to bolster their own strategic reserves back in October 21, 2010 commodities traders’ around the world got slightly panicky that this might affect the consumer electronics, hybrid car and wind turbine generator industry. Such is the usefulness of rare earth metals in our contemporary 21st Century society that the lone commercial producer of rare earth metals now has gained tremendous geopolitical clout. Given the difficulty of new and former rare earth producers to start their own rare earth metal industry, is it really that difficult to extract the valuable commodity from the ground that it is compared to “wringing blood from stone”?

The rare earth elements, though not exactly abundant, are not at all rare; they are in fact widely distributed in nature. In actuality, the term “rare” is more descriptive of these elements’ “unusual” properties than of their relative abundance on our planet. The order of magnitude of abundance ranges from lutetium at 0.7 parts per million of the Earth’s crust to 44 parts per million for cerium. Distribution wise, even our seas contains 1.8 long tons of cerium and 1.4 long tons of lanthanum per cubic mile of seawater. Unfortunately at this concentrations, it is too diluted a form to be extracted in an economically viable manner using present technology.

Commercially viable rare earth minerals like monazite, samarskite and even uranite are widely distributed across the Earth’s surface, but mining and processing rare earth metals in a commercially viable manner into their commercially viable forms for the world’s commodities markets is another thing entirely. Samarskite was used to be extensively mined in the continental United States, but since 1990, it can no longer be done in a commercially viable manner due to wage, miner safety and environmental concerns.

From the Periodic Table’s perspective, the rare earths are conveniently grouped according to the solubility behavior of their sulfates or by the slight differences of their basic strength. Their similarities in electron configuration suggested similarities in chemical behavior. The trivalent ions are especially similar in forming salts of nearly identical solubilities, hydroxide strength, and complexing tendency. The latter property and small differences do provide a method of separation.

Rare earth metal manufacturing could be considered a relatively young branch of metallurgy. Until the middle of the 1940s, chemical separation of one rare earth element from another was achieved only by the most tedious means of fractional crystallization of the double sulfates, oxalates, and nitrates. The very slight differences in salt grain size from one rare earth element to another provides very slight differences in solubilities of such compounds. Literally thousands of individual manual operations were required even for crude separations. The need for and interest in the individual members of the rare earth series of elements led to more efficient means of separation. Separation of rare earth ions from each other is currently achieved most economically and in the highest purity by either ion-exchange or solvent-extraction procedures.

Unlike that of the chemical separation and processing of the platinum group of metals which remained a proprietary industrial / commercial / corporate secret, the post World War II scientific interest in are earth metals had made the laboratory separation of them an open knowledge by virtue of academic freedom and a widely-distributed academic pursuit. The knowledge of efficiently separating rare earth metals from their ores and from each other eventually reached the People’s Republic of China.

Slave wages, very lax mining safety, environmental and miner’s health concerns had eventually made Mainland China the sole commercially viable provider of rare earth metals for the world’s commodities markets. The ridiculously low prices are conveniently passed on to their miners, which doesn’t say much about where the Mainland Chinese rare earth metal industry stands when it comes to corporate social responsibility. Mining rare earth metals and processing their ores is indeed like wringing blood from stone in more ways than one.