BUENOS AIRES, Feb 1 (Reuters) - Argentine tax receipts rose 46.6% year-on-year in January to 772.8 billion pesos ($8.85 billion), the economy ministry said on Monday. Collection of export duties rose 231.2% in January, the ministry explained in a statement, as a slew of port strikes slowed agricultural exports in December. This contributed to a rush of pent-up shipments in January, it said. Higher international commodity prices also contributed to the boost in January tax receipts, the ministry said. Argentina is a major grains exporter.