Njerwa zosawotchedwa ndi mtundu watsopano wa zinthu zapakhoma zopangidwa ndi phulusa la ntchentche, cinder, malasha gangue, slag ya mchira, slag yamankhwala kapena mchenga wachilengedwe, matope a m'mphepete mwa nyanja (chimodzi kapena zingapo mwazinthu zomwe zili pamwambazi) popanda kutentha kwambiri.

M'zaka zaposachedwa, kuwonongeka kwa zomangamanga kukuchulukirachulukira, zomwe zabweretsa mavuto ku dipatimenti yoyang'anira mizinda. Boma lazindikira pang'onopang'ono kufunika kwa chithandizo chazinthu zowononga zomangamanga; Kuchokera kumalingaliro ena, zinyalala zomanga ndi mtundu wachuma. Pambuyo pa mzere wa njerwa wa Leishi Chengxin, ukhoza kukhala chinthu chatsopano champanda chosakwanira masiku ano, ndipo chagwiritsidwa ntchito mokwanira.

Fly ash ndiyo imaipitsa kwambiri chilengedwe. Ku China, zotulutsazo zimafika matani masauzande ambiri, ndipo ambiri aiwo sagwiritsidwa ntchito, omwe samangowononga chuma, komanso amayambitsa kuwonongeka kwakukulu kwa chilengedwe. Ndipotu, fly ash ndi yabwino kupanga njerwa zopangira. Pambuyo pa mzere wopanga njerwa za Leishi Chengxin, ukhoza kukhalanso chida chatsopano champanda chosakwanira masiku ano, chomwe chagwiritsidwa ntchito mokwanira.

Osati zinyalala zomangira, phulusa la ntchentche, michira, kusungunula zitsulo ndi zinyalala zina zolimba, makina a njerwa osawotchedwa a Lei Shi Chengxin amatha kusandutsa zinyalala kukhala chuma, ndipo "mwana" wopangidwa akugwiranso ntchito pakusunga madzi, khoma, nthaka, dimba ndi zina!