U.S. Silica's SandBox Unit To Appeal Patent Office Decision

KATY, Texas, Sept. 16, 2019 /PRNewswire/ -- U.S. Silica Holdings, Inc. (NYSE: SLCA) announced today that its SandBox Logistics^TM business unit intends to appeal a recent United States Patent Office decision to invalidate challenged claims in one of the patents at issue in SandBox's lawsuit against Proppant Express Investments, LLC (PropX), joining other pending appeals filed by both parties in the on-going dispute between SandBox and PropX. 

''We have been pleased with the Patent Office's decisions upholding multiple claims across three of four patents challenged by PropX in other IPRs that have reached a final decision. It's important to note that in the underlying case against PropX, we only need to establish infringement of one claim and several of the claims in suit have been upheld in IPRs.  Although we believe this latest decision was wrong, our success rate in these IPRs is well above the statistical norm and positions us very well in the litigation," said Bryan Shinn, U.S. Silica president and chief executive officer. "SandBox maintains a robust portfolio of more than fifty issued U.S. patents encompassing hundreds of claims. We will continue to vigorously defend our intellectual property portfolio,'' he added.

About U.S. Silica

U.S. Silica Holdings, Inc. is a performance materials company and is a member of the Russell 2000. The Company is a leading producer of commercial silica used in the oil and gas industry, and in a wide range of industrial applications. Over its 119-year history, U.S. Silica has developed core competencies in mining, processing, logistics and materials science that enable it to produce and cost-effectively deliver over 1,500 diversified products to customers across our end markets. U.S. Silica's wholly-owned subsidiaries include EP Minerals and SandBox Logistics^TM. EP Minerals is an industry leader in the production of products derived from diatomaceous earth, perlite, engineered clays, and non-activated clays. SandBox Logistics^TM is a state-of-the-art leader in proppant storage, handling and well-site delivery, dedicated to making proppant logistics cleaner, safer and more efficient. The Company currently operates over 25 mines and production facilities. The Company is headquartered in Katy, Texas and has offices in Reno, Nevada and Chicago, Illinois.

U.S. Silica Holdings, Inc.

Michael Lawson
Vice President of Investor Relations and Corporate Communications
(301) 682-0304
lawsonm@ussilica.com

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SOURCE U.S. Silica Holdings, Inc.