The technology is hoped to ease the current construction sand shortage

The sea sand, after having chlorine irons neutralized, can be converted to construction sand meeting Vietnamese standard TCVN 7570:2006. 

The technology is hoped to help ease the current construction sand shortage.

Chlorine iron content 10 times lower 

In mid-March 2018, the Laboratory of Corrosion Research and Construction Protection under the Institute of Construction Science and Technology announced the findings of research. 

A sample of saline sand brought from Ba Ria - Vung Tau province with salt content (chlorine) of 0.255 percent, after being processed with technology of amateur inventor Vo Tan Dung in Can Tho City, who is director of Phan Thanh Company, saw the chlorine iron (Cl-) content fall to 0.018 percent.

Prior to that, in 2017, Dung many times experimented with the technology upon the sand samples taken from many different sources, including Ka Long River in Mong Cai, Quang Ninh province, Ninh Thuan, Phu Quoc Island and Thi Vai – Cai Mep area.

The Can Tho Quality & Measurement Center, Southern Building Materials Sub-Institute and the Institute of Construction Science & Technology all reported that processed sand meets the requirements to be used as construction sand, especially in Cl- content.

The sea sand from Ka Long estuary, for example, had Cl- content of 0.24 percent initially and 0.007 percent after the processing as recognized by the Can Tho Quality & Measurement Center. 

That was 14 times lower than the Vietnamese standard TCVN 7570:2006. 

The sand from Binh Thuan, after processing, had Cl- content of 0.005 percent, or 10 times lower than the Vietnamese standard, according to the Institute of Construction Science & Technology.

Nguyen Duc Thang, a specialist at the institute, confirmed that salty sand, after two cleaning steps with Dung's sand washing machine, had chlorine ion content low enough to make reinforced concrete structures. 

This is significant as it lifts the concern about the lack of sand to be used in special areas where it is impossible to carry sand from the mainland.

The machine not only cleans sand, but also sorts the sand. The type of sand which is washed the most is used for construction mortar, because it contains mud and organic matter.

According to Cung, many people may think that sand processing increases the production cost. However, the machine helps classify sand, and large-grain sand is used for concrete sold at higher prices. 

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