A two-step chemical vapor deposition method is recently developed in industries for fabricating low-hydroxyl quartz glass. In this technique, bubbles are often trapped in molten quartz due to its highly viscous feature. Main purpose of this study is to analyze the bubble-group transport behavior in molten quartz and to explore effective methods for accelerating bubble rising and removal using simulation methods. An integrated numerical model is established with considering detailed heat transfer and fluid flow in the melting furnace, as well as discrete bubble tracking in molten quartz. Reliability of the simulation results is qualitatively validated by comparing with the theoretical calculations using classical Stokes and Hadamard-Rybczynski equations. Based on the results, it takes hundreds of hours for bubbles to escape from molten quartz in a typical heating furnace, which is unacceptable in practical fabrication. The temperature influence on bubble rising is studied in detail, which shows that increasing temperature could greatly enhance the fining efficiency through decreasing the melt viscosity. Finally, a novel method for accelerating bubble rising is put forward by using a rotating cone stirrer. Under the stirring effect, bubbles rise rapidly in molten quartz at the early stage, which is helpful for reducing the fining time. The rotating speed and size parameters of cone stirrer are further studied for their influences on the bubble rising behavior. Based on these findings, efficient fining of molten quartz is obtained by proper controlling of the stirrer. (C) 2019 Elsevier Ltd. All rights reserved.