Abstract:
PT. Hydrotech Metal Indonesia (HMI) is a subsidiary of the Trinitan Group
which was founded in 2020. Hydrotech Metal Indonesia (HMI) focuses on research
and development of mineral processing technology in Indonesia. One of the
activities currently being carried out is the extraction of nickel from limonite ore
using STAL (Step Temperature Acid Leach) technology (PT. Hydro Metal
Indonesia. 2020). In extracting the metal contained in limonite ore with the STAL
method. it produces saline water with a content (Total Dissolved Solid / TDS) of
more than 120.000 ppm. Meanwhile. the Regulation of the Minister of the
Environment of Indonesia No. 5 of 2014 concerning wastewater quality standards
for businesses and or activities that do not yet have a wastewater standard. one of
the parameters is that soluble solids (Total Dissolved Solid / TDS) must be in the
range of 2000 – 4000 ppm. Therefore. it is still necessary to carry out a process to
reduce the TDS content in the water to be discharged and also to utilize saline water
waste to become a useful product.
The production capacity of Magnesium Sulfate is 20.000 tons/year it can be
obtained with Saline Water waste through ultrafiltration after processing Saline
Water in the Screen Filter. then proceed through the main process of nanofiltration.
xiii
Teknik Kimia Serra Yunita (1141800001)
Institut Teknologi Indonesia Fathan Affan B P. (1141800004)
Muhammad Latif F. (1141800028)
Pra-Rancangan Pabrik MgSO4 dari Limbah Saline Water
Dengan Kapasitas 20.000 Ton/Tahun
magnesium sulfate concentration can be obtained through a triple effect evaporator.
then the crystallization process to get solid salt. and the drying process to obtain
Magnesium Sulfate. Supporting facilities (utilities) needed for this plant include:
electricity up to 20.679.29 kWh. and diesel fuel up to 1.42 L/day. The legal entity
of this company is a limited liability company (PT). the organizational structure is
led by a director who supervises 136 employees. This factory operates 24 hours for
330 days. Based on the economic analysis. it can be concluded as follows:
a. Total Investment = IDR 393,708,076,818.16
b. Own Capital (66 %) = IDR 249,299,137,913.74
c. Bank Loans (34%) = IDR 144,408,938,904.42
d. Interest rate per year = 7,5%
e. Loan term = 10 years (grace period 1 year)
f. BEP (Break event point) = 38%
g. NCFPV with interest rate 7,5% = IDR 995,756,940,212 (Positive)
h. IRR (Internal Rate of Investment) = 42.58%
i. MPP (Minimum Payback Period) = 3 years 11 months 19 days
Based on the results of the economic analysis of NCFPV. IRR. and MPP. it
can be concluded that the magnesium sulfate factory is feasible to be established
(feasible).
