Method for measurement of weight concentration of clay in a sample of a porous material

A method for determining weight concentration of clay in a sample of a porous material comprising:

• selecting a water-soluble salt of a metal, the salt entering into a selective ion exchange reaction with clay and having with the general formula R+M−, where a R+ metal and an anion M− are selected in accordance with the table of solubility of inorganic substances in water so as to provide the water-soluble salt of a metal,
• marking clay by mixing the clay with a water solution of the selected water-soluble salt of the metal,
• removing residues of the salt of the metal that have not interacted with the clay,
• performing X-ray fluorescent spectroscopy of the marked clay and the sample of the porous material and determining a content of the metal in the marked clay and a natural content of the metal in the sample of the porous material respectively,
• preparing a solution of the marked clay with the required concentration by mixing the marked clay with water,
• pumping the prepared water solution of the marked clay through the sample of the porous material,
• drying the sample,
• dividing the sample into at least two segments,
• performing X-ray fluorescent spectroscopy of each segment and determining a content of the metal in each segment and
• calculating weight concentrations of clay retained in each segment of the porous material as
• n
• cl
• i
• =
• η
• Σ
• i
• -
• η
• n
• η
• cl
• -
• η
• n
• where ncli is weight concentration of clay in the ith segment, ηΣi is the content of the metal in the ith segment, ηcl is the content of the metal in the marked clay, ηn is the natural content of the metal in the sample of the porous material.