You're interested in the technological changes that marked the change from one culture to another? These kind of questions intrigue me too and also interested European archaeologists from the 19th C on.

The broad brush picture they paint is of successive waves of technological advances, spreading across the map like ripples on a pond. First the Neolithic Revolution, then Copper, Bronze and Iron Ages.

The Neolithic Revolution (c. 5000 BCE) is marked technologically by the use of ceramics and, with more impact, the adoption of agriculture. Farming led materially to settlement and increased populations, and these in turn to social stratification and institutions of leadership, ownership, and trading. These are some hallmarks of civilisation (an ill-defined term).

The first metal worked was copper, sometimes available as native metal which was soft enough to be cold-wrought with a stone hammer.

No special kiln or smelter is required to melt copper (melting point ~1000 C) - just an ordinary if hot fire. Fire would be known for its transformative actions (cooking, pottery), so it would not be a far step from hammering native copper to melting it in a ceramic crucible and then casting liquid metal into a desired shape, usually an axe.

Copper tools were used to craft the Pyramids, and a copper axe was amongst the possessions found with Otzi when he fell in the Italian Alps some 5,000 years ago.

Shortly thereafter, so the story goes, some bright early alchemist would've added the rarer, softer metal tin (melting point 232 C) to his crucible of molten copper, producing the paradoxically much harder alloy metal, bronze. Bronze as a material did not, in contrast to copper, occur naturally, and it's superior hardness and ability to keep an edge offered real practical advantages.

Now, if your talking extremely high temperatures, then we're into the smelting, casting and smithing of iron. Iron doesn't occur naturally and smelting it out of its ore requires yet more elaborate resources, such as charcoal fuel, bellows and smelter, and the specialist skills of a smith to work the metal.

References: Gordon Childe. The Prehistory of European Society. 1958. Colin Renfrew. Archaeology and Language: The Puzzle of Indo-European Origins. 1987

Some copper deposits also contain arsenic, so that simply melting this copper ( a ceramic pot with a cover, a supply of charcoal, and something like a bellows ) would produce an arsenical bronze. This is something you find in a number of early artifacts, like Egyptian knives, and other tools. The Wikipedia ( sorry) article on arsenical bronze discusses some of the theories about how it all came about, but really it was not that hard to figure out, by trial and error. Native copper exists in metallic form; break off a bit, and you can just use it. Figure out how to melt it, and you can make bigger things from it. The copper rocks underneath the surface copper rocks, which contain more arsenic, make a tougher copper. Some other rocks, that contain antimony, will make even tougher copper when mixed with the copper rocks. Assume people are not stupid, all the time, and eventually you get bronze.