Boeco Qualitative Filters

Grade 1288 - wide-pored, spongy structure, soft, very high rate of filtration

• coarse-flocculent and bulky precipitates
• in particular hydroxides of iron
• aluminium and chromium
• sulphides of copper
• bismuth
• cobalt and iron
• various organic metal precipitates
• determination of silicon in the analysis of steel and pig iron, etc.

Grade 1289 - plain, medium wide pores, medium fast

• commonly used grade for analytical work
• coarser precipitates like sulphides of silver
• arsenic
• antimony
• cadmium
• lead iron and magnes
• lead chromate
• ammonium molybdate
• alkaline earth carbonates etc.

Grade 1291 - fine pored, very dense, very low rate of filtration.
Fine-grained precipitates cold-precipitated barium sulphate, meta-stannic acid.

Grade 292 - medium to slowly filtering, medium tight

fast filtration of fine precipitates such as

• calcium oxalate
• magnesium ammonium phosphate
• coarser forms of barium sulphate

Grade 292a - slowly filtering, narrow pores

filtration of fine precipitates such as

• lead dioxide
• calcium fluoride
• nickel sulphide
• zinc sulphide