09 April 2023
In an effort to implement sustainable business practices, PT Trimegah Bangun Persada, also known as Harita Nickel, processes nickel slag, which is residual waste from smelter processing, into high-quality premium building materials with economic value. Nickel slag is classified as one of the four B3 waste sources that are exempt from being classified as B3 waste or can be considered a by-product, according to Article 54 of Government Regulation (PP) Number 101 of 2014. The other three waste sources are fly ash, steel slag, and spent bleaching earth.
As stated on the official website of the Directorate General of Highways of the Ministry of Public Works and Public Housing, nickel slag has chemical compounds similar to those found in natural aggregates commonly used as construction materials. This indicates that nickel slag has the potential to be utilized as a construction material, thereby reducing natural resource exploitation.
Harita Nickel has developed various products made from nickel slags, such as bricks, precast and ready-mix concrete, road base and fields, soil improvers, growing media and fertilizers, mortar and slag cement, composite Portland cement, and geopolymer cement. The company's highest production from optimized nickel slag is bricks, with 40,000 units produced per day, which have above-average quality compared to similar materials.
According to Tonny Gultom, the Director of Health, Safety, and Environmental Operation Department of Harita Nickel Group, the utilization of nickel slag into bricks has undergone research and development for approximately one year. Tonny stated that the produced bricks have sufficient solidity and are heavier and stronger, owing to the formulation consisting of 85% nickel slag, 10% fly ash (residual coal-fired power plant ash), and 5% cement.
With this premium quality, the economic value of nickel slag bricks is around Rp 4,000 per unit, making them more expensive than ordinary bricks. This represents a potential additional income for Harita Nickel from the non-core business sector worth Rp 58 billion per year. However, the company has not yet marketed this product outside of Pulau Obi due to high logistics costs. For now, the company only fulfills local needs, such as for the construction of the New Residential Area of Desa Kawasi, which is designed with an eco-village concept, road infrastructure, and sidewalks.