An　acidic　mixture　of　sulfuric　and　fluosilicic　acid　(H2SO4+H2SiF6)　was　employed　as　lixiviant　to　enhance　leaching　of　lithium　from　lepidolite.　The　H2SiF6　was　obtained　as　a　byproduct　of　anhydrous　hydrofluoric　acid　production,　aiming　to　provide　HF　molecules.　It　was　found　that　the　HF　molecules　were　the　main　reaction　component　and　played　a　key　role　in　strengthening　the　dissolution　of　lepidolite.　Different　factors,　including　mass　ratio　of　ore/H2SO4/H2SiF6,　concentrations　of　H2SO4　and　H2SiF6,　leaching　temperatures　(40−80　°C)　and　time　(15−75　min),　were　investigated.　Moreover,　an　efficient　tubular　reactor　was　employed　to　improve　this　acid　leaching　system.　Under　the　optimal　conditions　(ore/H2SO4/H2SiF6　mass　ratio　of　1:0.8:1.6,　80　wt.%　H2SO4,　15　wt.%　H2SiF6,　80　°C,　15　min),　97.9%　of　Li,　96.4%　of　K,　97.6%　of　Rb,　96.7%　of　Cs　and　81.4%　of　Al　(mass　fraction)　were　leached.　Additionally,　a　two-step　thermal　process　was　proposed　to　remove　fluorine　of　leaching　slurry.　This　acid　treatment　using　an　acidic　mixture　of　H2SO4　and　H2SiF6　in　a　continuous　tubular　reactor　shows　potential　as　an　alternative　process　to　extract　lithium　from　lepidolite.　©　2021　The　Nonferrous　Metals　Society　of　China