Study of using Dolomite as Starting Material Resource to Produce Magnesium Oxychloride Cement

Abstract

In this paper, the starting materials necessary for producing magnesium oxychloride cement (MOC) were produced from dolomite ore using leaching-carbonation-evaporation-pyrohydrolysis processes. The influences of the molar ratio of MgO/MgCl 2 (M x) and H 2 O/MgCl 2 (H y) on the properties of the MOC (cured for 7 days) were determined using physico-mechanical methods. SEM and XRD analyses were conducted to determine the change of phase and microstructure of the selected 7-day MOC depending on the production conduction. The experimental results show that the best mix proportion of 7-day MOC was found to be M 6.06 H 14 and its thermal conductivity, flexural strength, and compressive strength values were found to be 1.202 W/mK, 4.22 MPa, and 87.7 MPa, respectively. The water resistance of the MOC was improved by a small amount of H 3 PO 4 (4% of MgO by weight). Consequently, if MOC is produced from dolomite, high-purity synthetic aragonite and CO 2 would be obtained as byproducts, which are strongly demanded.

Influence of Waste Plastic Aggregate and Water-Repellent Additive on the Properties of Lightweight Magnesium Oxychloride Cement Composite

“…In literature, there are studies that report on improving the poor water resistance of MOC cement. Authors investigated the use of additives as soluble phosphates [18], fly ash [11,17,19,20], rice husk ash with addition of phosphoric acid, calcium lignosulfonate, and acrylic emulsion [21], the phosphoric acid [22,23], silica fudehume [19], and glass powder [21]. The evaluation of the MOC cement composites water-resistance is to date done only by the compressive strength measurement before and after the immersion in water.…”

Preparation of periclase (MgO) nanoparticles from dolomite by pyrohydrolysis–calcination processes

“…Therefore, each product obtained can be used in many industrial applications such as toxic waste absorbent, ceramic material, and production of magnesium oxychloride cement. The use of these products in a construction industry for preparing negative carbon‐based magnesium oxychloride cement has also been further investigated .…”

Application of a New Computational Method to Calculate the Mixture Composition of Magnesium Oxychloride Cement

“…Magnesium oxychloride cement (MOC) is formed by the addition of a magnesium chloride solution (MgCl 2 -H 2 O) to a fine powder of magnesite or dolomite with a major component being caustic MgO a [1,2]. Compared to Portland cement, it possesses many advantages, including a lighter weight, a higher strength, no need for humidity curing, antifreeze and resistance to halogen [3,4].…”

“…[6][7][8][9][10][11]. Generally, the hydration products of mixing magnesium oxide, magnesium chloride and water are phase 3 (3Mg(OH) 2 •MgCl 2 •8H 2 O) and phase 5 (5Mg(OH) 2 •MgCl 2 •8H 2 O) [1,[3][4][5][6], and the composition of the hydration products depends on the molar ratios of MgO a /MgCl 2 and H 2 O/MgCl 2 [12,27]. The research results demonstrate that the performance of MOC approaches the optimal when the value of n (MgO/MgCl 2 ) reaches 4-6 [13].…”