English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The effect of various types of mineral acids in activating the silica of volcanic ash of Mount Sinabung has been carried out. The use of various types of mineral acids is aimed at reducing impurities in the form of metals contained in the ash so that it can increase the SiO 2 content in the ash. In the treatment, volcanic ash is prepared beforehand by grinding and sieving with a 200 mesh sieve. The sieved ash was then added with mineral acids, namely HCl, HNO 3 and concentrated H 2 SO 4 and heated at 100 o C for 2 hours. After that, it was neutralized with distilled water and in an oven at 120 o C for 6 hours and characterized using XRF to determine the impurities that had been lost. Based on the results obtained using XRF characteristics, the SiO 2 content of volcanic ash activated with HCl was 80,23%, HNO 3 was 77,23% and H 2 SO 4 was 76,89%. This shows that activation using HCl is more optimal than using HNO 3 and H 2 SO 4 .

ACTIVATION OF SINABUNG MOUNT VOLCANIC ASH USING VARIOUS MINERAL ACIDS