Vietnam Cement Corp (VICEM) has used the COVID-19 period to increase its use of alternative fuels and waste raw materials. ICR highlights Tai Nguyen and Moi Truong's recent report on the projects that have seen the Vietnamese cement company reduce its production costs and its CO2 emissions over the last three years.

VICEM started testing the treatment of ordinary industrial waste as an alternative fuel from the end of 2019. Since 2020 the company has treated waste, mainly from the leather, footwear and textile industries, at seven production lines in five of its cement plants. The total volume of waste used as an alternative fuel for VICEM’s cement plants totalled nearly 120,000t in 2020. Following an optimisation drive in 2021, VICEM plans to treat about 276,000t of waste in 2022.

Currently, out of Vietnam's 97 cement production lines only three are licensed to treat hazardous waste: INSEE Cement Co (Kien Giang), Thanh Cong Cement Co Ltd (Hai Doung) and Nghi Son Cement Co (Thanh Hoa). However, VICEM But Son received approval from the Ministry of Natural Resources and Environment to launch a trial of hazardous waste treatment in November 2021 and the unit has successfully treated more than 4172t of hazardous waste. The unit is supported with a treatment cost of VND400,000/t during the trial period, which is paid by the collector.

At the Ha Tien and Binh Phuoc plants, the company is surveying the sources of hazardous waste supply with a view of starting co-processing by the end of 2022. 

Slag and fly ash usage
The total volume of fly ash and slag used throughout VICEM in the 2016-20 period is more than 7.7Mt. In 2021 the total amount of fly ash and slag used reached almost 2.6Mt. The 2022 plan uses more than 3Mt, equivalent to a utilisation rate of 11.5 per cent. The use of fly ash and slag contributes to the successful implementation of the goals of the Government's Strategy on Development of Building Materials in 2021-30, with a vision to 2050.

Treated sludge
Since 2020 VICEM has treated sludge from industrial parks and wastewater treatment plants to substitute part of the clay in cement production at five kiln lines in the Hoang Thach, But Son, Ha Long and Ha Tien 1 cement plants. In 2020 the total treatment volume was more than 15,000t of sludge, rising to 70,000t in 2021. In 2022 VICEM plans to treat 86,000t of sludge and the Ha Long plant aims to treat 15,000t of sludge.

Artificial gypsum
VICEM has also researched and used artificial gypsum to replace natural gypsum in cement production. In 2020 the amount of artificial plaster VICEM used was 25,000t, nearly quintupling to 122,000t in 2021. VICEM Song Thao has used artificial gypsum to replace 100 per cent of natural gypsum in its production. In the 2022 plan, VICEM will use over 150,000t of artificial gypsum out of the total gypsum demand of nearly 800,000t for VICEM's cement production.

Debottlenecking
VICEM has also been actively debottlenecking plants to increase equipment efficiency and productivity, and reduce consumption. This is also associated with the goal of using waste as an alternative fuel with low-grade coal.

The group is also modernising its clinker lines. For example, the first production line of But Son was implemented in 2019, and productivity increased by nearly nine per cent from 4000 to 4350tpd of clinker, while the plant's heat consumption of ≤800kcal/kg clinker was reduced by 30kcal/kg clinker. For example, the third line of Hoang Thach, implemented in 2020, saw productivity rise by 15 per cent from 3300 to 3800tpd of clinker, while heat consumption of ≤800kcal/kg clinker was reduced by 39kcal/kg clinker. Similarly, the Hai Phong line was commissioned in 2021, increasing productivity by 21 per cent from 3300 to over 4000tpd of clinker, while heat consumption fell from ≤800kcal/kg clinker to ≤742kcal/kg clinker.

In March 2022 VICEM's Hoang Mai plant carried out repair work to increase kiln capacity from 4000 to 4500tpd of clinker (up 12.5 per cent). As a result of the repair work, heat consumption also fell to ≤800kcal/kg clinker. 

Future developments
The ‘Greening Cement’ project, launched in April 2022, in Ha Long City, Quang Ninh province, is VICEM’s latest initiative to create a circular economy and increase its co-processing. It was formed based on the cooperation between VICEM, FLSmidth and partners, and partly funded by the P4G organisation with the goal of sustainable development and green cement production. VICEM wants to cut fossil fuels, increase waste treatment and establish a supply chain of industrial and urban waste in a circular economy initially for its Ha Long cement plant and ultimately for all its cement plants. In 2022 the project will entail a feasibility study, and in 2023 technical design and policy issues will be implemented along with FLSmidth’s equipment.

Published under Cement News