methods and systems are disclosed employing a quad - tier shale shaker for processing a mixture of drilling fluid and solids which solids include , in one aspect , lost circulation material . this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims , 37 c . f . r . 1 . 72 .