Ozonation for destruction of cyanide in canadian gold mill effluent - a preliminary evaluation

Abstract

A literature search was made to determine whether ozonation would be technically and economically attractive for the treatment of cyanide-bearing gold mill effluents. The publications covered in this survey were those concerned with (1) recent advances in ozone generation and gas-liquid contacting devices of interest to cyanide oxidation, (2) conditions for a rapid and complete decomposition by ozone of both simple and complex cyanides commonly found in gold mine effluents and (3) cost of ozonation under these conditions. This state-of-the-art review shows that ozonation might be a valid alternative to conventional methods of cyanide detoxification of gold mill effluents. The ozonation process at the time of writing is relatively high in capital cost but low in operating costcompared with conventional processes.

Electrochemical treatment of diluted cyanide aqueous wastes

“…Ozonization is a promising technology to treat cyanide effluents. Ozone is a strong oxidant and produces non‐toxic products 5. Advanced oxidation processes, which involve the in‐situ generation of powerful chemical oxidants such as the hydroxyl radical ( • OH), are more reactive and much faster compared with the ozone molecular process and have recently emerged as an important class of technologies for accelerating the oxidation and destruction of a wide range of contaminants in polluted water 1, 6–8.…”

Pretreatment with Ozone for Gold and Silver Recovery from Refractory Ores

“…Some research work has been done regarding the use of ozone in the mineral industry, mainly on the treatment of effluents containing cyanide (Mathieu, 1977;Rowley and Otto, 1980), and on the oxidative leaching of copper ores (Roca et al, 2000). In this research work the use of ozone is proposed as oxidative pretreatment for gold and silver refractory ores with the aim of modifying the pyritic matrix and thus exposing the precious metals to cyanide.…”

Energy efficient—Advanced oxidation process for treatment of cyanide containing automobile industry wastewater

“…H 2 O 2 , a strong oxidizing agent, oxidizes CN to nontoxic compounds via cyanate (CNO − ) following hydrolysis reaction. CN destruction using a O 3 /CN system has been employed for a number of bench scale studies [12][13][14][15][16][17][18][19][20] that demonstrated the first reaction to be extremely rapid while the second reaction of cyanate oxidation by O 3 to be a slower one. The use of O 3 offers a specific advantage over H 2 O 2 that little secondary products are formed after the treatment.…”