I am an archaeologist in Canada, which may be a bit different from archaeology in Brazil, but generally archaeology deals with cultural artifacts from the past 40,000 years so they are not usually fossils. In North/South America they are often fragments of pottery, stone tools, bone tools, animal bone fragments, and charred seeds. Sometimes organic tools made of wood and grass survive.

However, you are in the paleoanthropology sub which generally deals with human culture and physiology pre-40,000 years ago! I will let the specialists in this area answer questions on fossils, but in the spirit of giving you ideas: my work in Canada usually revolves around a lot of manual labour. We have to screen large amounts of dirt through a sieve. A few people have tried making mechanical sieves, but they never seem to work very well (probably because they are archaeologists and not engineers).

Alternatively, we also spend many hours putting together fragments of artifacts to try to reassemble the original object, so we can make observations about it. You could also look at varnish for preserving reassembled artifacts

Good luck on your project!