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The proneness of container glass obtained from a mixture of green cullet with 10 -50% colorless or brown cullet to foam up is evaluated. An indirect method is used: the apparent density of pelleted samples heat-treated at temperatures 800, 1000, and 1200°C is monitored. It is determined that the density reaches a maximum value at 1000°C as a result of sintering and compaction and up to 1200°C it decreases because of a decrease of the solubility of gases and foaming. The density of samples sintered at 1200°C from a mixture of oxidized (green) and reduced (brown) glass decreases, while for a mixture of oxidized (green + colorless) glasses it increases. Therefore loading brown cullet into a furnace producing green glass is impermissible because there is a high risk of the melt foaming up.It is well known that the use of recycled cullet in glass production makes it possible to economize raw materials and energy resources substantially. Statistically, the cullet fraction in container production is > 60% [1]. For making container glass Russia needs about 600´10 3 tons of container culler per year [2].Secondary cullet is always contaminated with impurities of inorganic (inclusions of a refractory, metal foil, and so on) and organic (corks, labels, remains of shipment containers, and so forth) origin. It is reported in [3] that the presence of even small crystals, ceramic, stones, particles of porcelain results in rejection of the final product. Negligible quantities of iron or other ferrous impurities change the color of the final product. For example, the presence of 0.4% green glass in a melt of colorless glass cannot be neutralized, even chemically.When a mixture of batch and cullet is heated, organic contaminants carbonize and partially interact with CO 2 (as a result of the decomposition of the carbonate component of the batch), forming CO. In the process, the reduction of sulfates and Fe 3+ to sulfides and Fe 2+ respectively intensifies.Between 1000 and 1250°C the sulfides and sulfates react, forming sulfur containing gases. The retention of sulfates weakens, and finally the glass can contain sulfur only in the form of sulfides [4], which signifies degradation of the fining of the melt and a change of the color hue (and even the color itself) of the glass.For this reason, the quality criteria for recycled cullet must take account of the listed contaminants as a source of defects in the finished product [1]. On the whole the cullet preparation process must include sorting to remove foreign inorganic an organic contaminants, separation of the glass by color and hue, washing, comminution and magnetic separation, making it possible to remove from the prepared product "grounds" of metal from the milling equipment.European glass producers impose heightened requirements on the purity of recycled glass and the preparation of high-quality container cullet. For this reason there are a number of firms that specialize in making facilities for separating glass from ferrous metals, rocks, ceramic, and so on [3] and sorting by c...