(1) Pretreatment tuaj yeem tshem cov paug, oxide nplai, vuam slag, thiab lwm cov khoom tawg ntawm sab hauv phab ntsa ntawm cov kav hlau. Nws tseem npaj sab hauv ntawm cov yeeb nkab steel thiab txo cov kev ntxhov siab sab hauv. Qhov no zoo ua haujlwm lub neej ntawm cov yeeb nkab steel, minimizes sab hauv kev xeb, thiab yog li txhim kho kev txhim kho sab hauv thiab sab nraud ntawm cov yeeb nkab.
(2) Txuas ntxiv, Pretrealment ua kom cov kev sib txhuam ntawm cov kav hlau sib txhuam ntawm cov yeeb nkab hlau thiab cov yas ua kom lawv lub zog ua kom tau zoo.
