The present invention relates to novel microporous zirconium silicate compositions that are formulated to remove toxins, e.g. potassium ions, from the gastrointestinal tract at an elevated rate without causing undesirable side effects. The preferred composition has at least 95% ZS-9. These compositions are particularly useful in the therapeutic treatment of hyperkalemia. These compositions are also useful in the treatment of chronic kidney disease, coronary vascular disease, diabetes mellitus, and transplant rejection.
