<p>The State of Sinaloa, in Mexico, has significant gold deposits, which are exploited by artisanal miners using mercury. This process is dangerous, inefficient, and restricted, limiting gold recovery (30%) and excluding the extraction of silver and other metals present in the ore. This study presents an alternative method for recovering gold and silver. The ore in this region exhibits refractory characteristics that hinder its metallurgical processing, such as the presence of montmorillonite, a clay with high adsorption capacity. Gold recovery with cyanide reaches 76% and presents high consumption of leaching reagents (78% for cyanide). However, the use of thiourea in the presence of peroxide and oxalate improves the gold recovery to 98% and increases the process efficiency. However, silver recovery remains low owing to the refractory nature of the ore. Addition of oxalate reduces the consumption of leaching agents, and the peroxide acts as an oxidizing agent for gold extraction.</p> Graphical Abstract <p></p>