To add details and background

November 19 (Reuters) - MB Materials said on Wednesday it will build a rare earth metals refinery in Saudi Arabia in partnership with the U.S. Department of Defense and the state-owned Saudi Arabian Mining Company (Ma'aden) , to expand the processing of these important minerals in the Middle East.

The announcement comes as Saudi Crown Prince Mohammed bin Salman visits Washington this week for the first time since 2018, as part of his efforts to strengthen economic and security ties between the two countries.

Reuters reported in April that Maaden was considering a rare earth mineral processing partnership with MB Materials.

* A complex refining process

Shares of MP Materials , which operates the only U.S. rare earth mine , rose 4.2 percent at the start of trading. The company agreed in July to an investment from the Pentagon that will make Washington its largest shareholder.

Under the deal, MB and the US Department of Defense, through a joint venture, will own a 49 percent stake in the refinery , with Ma’aden owning the remaining 51 percent.

China dominates the global refining and extraction of rare earth minerals, which are vital to many key technologies. Beijing has imposed restrictions on exports of these essential minerals during periods of trade tension, prompting Washington to seek alternative sources.

At the same time, Saudi Arabia’s growing mining industry is a key pillar of the Kingdom’s Vision 2030 to diversify the economy away from oil.

The facility will extract and refine rare earth minerals from the Kingdom and elsewhere, converting them into oxides of what are called heavy and light rare earth minerals, each with different commercial and military applications.

In the United States, MB faced difficulty in securing supplies of dysprosium and terbium, which are among the so-called heavy rare earth elements used in the manufacture of magnets for electric cars, fighter jets, and other products.

The materials, once processed, will be used in the US and Saudi manufacturing and defense industries, and will be sold to allied countries, according to MB.

MB has been working to improve the refining and purification process for rare earth elements in California since at least 2020. The traditional process for refining rare earth elements is polluting, expensive, and time-consuming, which has spurred scientists to find better methods.

Those who process rare earth elements must deal with 17 minerals, each with a size and atomic weight almost identical to the other elements, making the separation process complex.

These rare earth elements must be extracted in a specific order, a logistical challenge that would prevent Ma’aden and MB from selecting specific elements they might want during the processing within the Kingdom.

MB said it is also in discussions to support magnet manufacturing in Saudi Arabia or to cooperate in this field.

Trump ordered the Department of Defense to change its name to the Department of War, a change that requires action from Congress.

(Prepared by Abdul Hamid Makawi for the Arabic Bulletin - Edited by Ayman Saad Muslim)