An electrolytic metal extraction cell (10) is disclosed for the electrowinning of metals from dilute solutions of their salts. A thin-walled tube (12) formed from the metal to be deposited extends between a pair of plastic end caps (13 and 14). The upper and lower end caps (13 and 14) include respective fluid outlet and inlet pipes (22 and 23) having their axes perpendicular to the axis of the tube (12) and tangential to the annular cavity (24) between the tube (12) and a central tubular electrode (21), inducing a spiral or turbulent fluid flow within the annular cavity (24) which promotes even deposition of electrowon material onto the tube (12).