Trial by fire: Safely heating sand without it agglomerating?
Sand is not available as a reagent grade chemical, but rather is mineral origin particles of a size between 0.074 and 4.75 millimeters. Gravel is bigger, silt is smaller.
Pure silica (SiO$_2$) may melt at 1713$^o$, but the melting point of real sand is given as 1500 to 1610, and you can probably find some numbers outside that range.
Perhaps more of an issue than the exact melting point is how much are you preparing to treat? And with what heat source? And what sort of vessel are you going to contain the sand in while you heat it up and cool it down? And for what purpose?
Thin layers of sand (small overall quantity) may burn off organics relatively easily, say in a stainless steel measuring cup, with a propane torch  - although, the handle will get hot, so arrange some sort of apparatus to hold the vessel.
Different materials will need different temperatures and times to burn off completely; perhaps you can heat till smoke stops coming off and the sand looks like it is a bright red or orange color. I doubt that you would have to get to a yellow.