Pengaruh Non-Probability Sampling Batubara terhadap Parameter Dry Ash Antara Certificate of Analysis Loading dan Unloading

Denny Murdany Muchsin

doi:10.33322/kilat.v9i1.722

Abstract

Umpire test (referee test) may be conducted by the coal supplier based on the potential loss due to the difference Certificate of Analysis (COA) in both ports (loading and unloading). The purpose of the research was to determine a comparison of COA from non-probability sampling compiled with standard. The research method used quantitative methods by collecting COA data on both ports. These data on the receipt of coal was obtained from a coal-fired steam power plant (PLTU). A Sampling at both ports was conducted by the non-probability sampling method. The assumption was determined that the sample preparation and analysis process had complied with the American Standard Testing and Material (ASTM) standards. The ratio of ash (dry basis) in both COA to its average was processed statistically by taking confidence intervals with a confidence level of 95%. This research showed that the ratio was in the range of 10.213% up to 16.793%, exceeding precision 10% as required by ASTM D2234-16. Therefore, the comparison of COA data from non-probability sampling, could not be used as a reference for the doubt of the work of independent surveyors e.g. COA unloading, then it is technically that umpire test could not be conducted by such comparison.

Highlights

ABSTRAK Uji umpire boleh dilakukan oleh pemasok batubara didasarkan pada potensi kerugian akibat perbedaan Certificate of Analysis (COA) di kedua port
The comparison of COA data from non-probability sampling, could not be used as a reference for the doubt of the work of independent surveyors e.g. COA unloading, it is technically that umpire test could not be conducted by such comparison
Coal and Coke from Coal, USA: ASTM International, 2012. [10] ASTM International, D3180 - 15 Standard Practice for Calculating Coal and Coke Analyses from As-Determined to Different Bases, USA: ASTM International, 2015

Summary

METODE PENELITIAN

Proses penelitian ini meliputi pengambilan data sekunder, pengolahan data, dan analisa statistik. Pengambilan Data Sekunder Data-data sekunder yang digunakan di dalam penelitian ini adalah moisture in the analysis sample (% weight, as determined basis) dan ash (% weight, as determined basis). Data tersebut diperoleh dari dokumen COA loading dan COA unloading pada setiap lot penerimaan yang diterbitkan oleh lembaga surveyor independen yang telah terakreditasi KAN (Komite Akreditasi Nasional). Data sekunder yang diambil berasal dari proses penerimaan batubara oleh PLTU Teluk Balikpapan pada tgl. Pengolahan Data Sepasang data ash (% weight, as determined basis) yang berasal dari COA loading dan COA unloading dikonversi ke ash (% weight, dry basis) menggunakan formula sesuai ASTM D3180: [10]. Semua perhitungan tersebut dilakukan pada data tiap lot penerimaan batubara sehingga mendapatkan 60 data rasio yang akan diolah secara statistik untuk mendapatkan nilai rentang rasio pada tingkat kepercayaan 95%.

HASIL DAN PEMBAHASAN

Findings

KESIMPULAN DAN SARAN