Improvement Of Properties Of Iraqi Bentonite For Foundry Moulding Sands | ||
| Tikrit Journal of Pure Science | ||
| Article 1, Volume 14, Issue 3, December 2009, Pages 176-184 | ||
| Author | ||
| Ahid Younis Al-Mallah | ||
| Abstract | ||
| The deposit of bentonite (Upper Cretaceous and Danian ) is exposed at 35 km south of H3, western desert of Iraq. The bentonite consist of (55% -85%) highly crystalline (Ca , Na ) montmorillonite mineral, also palygorskite mineral and variable constituents include sepiolite, dolomite, calcite, francolite, quartz and lesser amount of barite and secondary gypsum. The bentonite is characterized by high content of calcite (5% - 15% ) and low cation exchange capacity ( 50 – 86 meq /100 gm ) . The slaking are common and the clay show low swelling power. The described properties lead to clay weak bonding properties for foundry moulding sands . Effort were made to enhance the green compression strength ,dry compression strength, plasticity and ability of dispersion, therefore the clay is subjected to purification and sodium carbonate activation according to production line (crushing-purification-activation-drying-milling-screening-end product) precede the application in foundry work. The results of quality control tests for treated clay are: humidity (2.35%), pH (9), colloidal content (100%), fineness (173%), L.O.I (13.6%) and swelling ratio (2 gm/ 31ml). After mixing with standard sand, the green compression amounts to (45-50 gm/cm²) and dry resistance to (1810-1930 gm/cm²). The end product comply with the standard specification of foundry moulding sands at Naser company/ Iraq . | ||
| Keywords | ||
| Bentonite; Foundry; moulding sands; Montmorillonite; Activation Sodiun; Carbonate; Traifawi; Safra | ||
|
Statistics Article View: 31 PDF Download: 8 |
||