Author 1:
Name & Surname: Zyryanov I. V.
Company: Yakutniproalmaz Institute, ALROSA (Mirny, Russia)
Work Position: Deputy Director for Science
Scientific Degree: Doctor of Engineering Sciences
Contacts: e-mail: ZyryanovIV@alrosa.ru

Author 2:
Name & Surname: Bondarenko I. F.
Company: Yakutniproalmaz Institute, ALROSA (Mirny, Russia)
Work Position: Academic Secretary
Scientific Degree: Candidate of Engineering Sciences

Author 3:
Name & Surname: Khon V. I.
Company: Yakutniproalmaz Institute, ALROSA (Mirny, Russia)
Work Position: Head of Division for Rock Fracture

Author 4:
Name & Surname: Chernykh E. N.
Company: Institute of the Earth’s Crust, Siberian Branch, Russian Academy of Sciences (Irkutsk, Russia)
Work Position: Senior Researcher
Scientific Degree: Candidate of Geological and Mineralogical Sciences

The work has been contributed to by R.Ya. Nikitin, Researcher, and A.V. Vasiliev, Principal Process Engineer, Yakutniproalmaz Institute.

The article describes the research that is topical for the diamond mining industry and is aimed to minimize damage of natural diamonds under drillingand-blasting in the course of deep-level open mining of kimberlite ore at ALROSA. Based on the theories developed in the mid-1900s and concerned with the blast effect in a solid medium, it is recommended to use air-decoupled charges in kimberlite blocks, which allows more uniform distribution of blast energy lengthwise the hole, reduces loss in diamond value (by estimate, to 8.7% of basic cost), optimizes grain-size composition of kimberlite after blast fragmentation and improves autogenous mill efficiency at dressing process stage. Experimental demonstration of these advantages has been carried out. A purpose-designed and successfully used unit for making air decoupling is a plastic plug manually installed in hole, at the basic part (bottom) of explosive charge to shut off the upper boundary of the air gap. Emulsion explosive IREMEX has for the first time been trialed and adopted as the basic part (bottom) of an air-decoupled charge. The authors describe the design and technology of air-decoupled explosive charges. Concurrently, in view of advancement of the hybrid open pit/underground mining methods and aiming at kimberlite mining safety, seismically safe parameters of large-scale blasting are elaborated, validated and stated in open pit mines of ALROSA. Plans for the future involve continuing in-depth study toward minimizing production-induced damage of natural diamond crystals in mining, pretreatment and dressing of kimberlites. 

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