luoyang longzhong heavy machinery co., ltd. (lzzg) is a global provider of process solutions for the sand washing industry. luoyang longzhong heavy machinery co., ltd. (lzzg) is a global provider of process solutions for the sand washing industry. since 2010, we have designed and manufactured many wet processing plants for our customers in the world. with reliable product quality and perfect after-sales service, lzzg has won great praise from customers and established long-term cooperative relations with customers in australia, canada, america, peru, indonesia, malaysia, philippines, korea and south africa etc.