3964

3742

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1386

شانزده، 119، [II]ص.: مصور، جدول، نمودار

ص.ع. به:فارسي و انگليسي

احمد منشي، رحمت الله عمادي

26/03/87

رضا مظفري نيا، فتح اله كريم زاده

مهندسي مواد

ID3742

به فارسي و انگليسي: قابل رؤيت در نسخه ديجيتال

AbstractThe demand for use of castables especially low cement castables and use of aluminamagnesia spinel MgAl2O4 to resist slag corrotion has been increased in recent years Spinelcan be prepared an added or made in situ by reaction between raw materials which is cheaperand more suitable Due to the expansion of spinel formation development of nano sizecrystals is preferred In order to obtain nano size in situ developed crystals of spinel in low cement castable in thisstudy kind and amount of raw materials kind of cement and other suitable binders differentaggregates particle size and firing temperature were considered Different compositions weremade and heated to 110 C 900 C and 1400 C for two hours and bulk density apparentporosity cold crushing strength were measured and XRD and SEM studies were performed Results indicated that by using calcined magnesia with calcined or reactive alumina and firingthe castable at 1400 C for 2hr nano spinels of 35 40nm are produced which are notdestructive and yield good mechanical properties For the first time hexa meta phosphate was used together with hydraulic cements XRD andSEM studies showed that MgP2O7 Mg3 PO4 2 and Ca3 PO4 2 are developed and at 800 1000 C that cement bonds are dehydrated these bonds provide the required strength for thelow cement castables Secar 71 cement gave better properties than other cements Calcinedbauxite proved to be better than other aggregates

احمد منشي، رحمت الله عمادي

رضا مظفري نيا، فتح اله كريم زاده