The past week has been eventful for North American stock markets, with the TSX and Dow Jones both closing at fresh highs. However, equities in Toronto gave up some of their gains, reflecting a mixed sentiment among investors. Among the standout performers in Canada, three companies have made significant headlines. PyroGenesis Canada Inc. (TSX:PYR, Forum), a technology provider focused on decarbonizing heavy industry, announced a notable partnership. HPQ Silica Polvere, a company in which PyroGenesis is opting for a 50 per cent stake alongside HPQ Silicon Inc. (TSXV:HPQ, Forum), signed a letter…